CI: submit_cache failures
https://travis-ci.org/pandas-dev/pandas/jobs/338476528

Lots of

```
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/algos.pxd.c: No such file or directory
```

<details>

```
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/algos.pxd.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/algos.pxd.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/algos.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/algos.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/algos_common_helper.pxi.in.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/algos_common_helper.pxi.in.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/algos_rank_helper.pxi.in.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/algos_rank_helper.pxi.in.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/algos_take_helper.pxi.in.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/algos_take_helper.pxi.in.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/groupby.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/groupby.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/groupby_helper.pxi.in.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/groupby_helper.pxi.in.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/hashing.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/hashing.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/hashtable.pxd.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/hashtable.pxd.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/hashtable.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/hashtable.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/hashtable_class_helper.pxi.in.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/hashtable_class_helper.pxi.in.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/hashtable_func_helper.pxi.in.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/hashtable_func_helper.pxi.in.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/index.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/index.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/index_class_helper.pxi.in.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/index_class_helper.pxi.in.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/indexing.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/indexing.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/internals.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/internals.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/interval.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/interval.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/intervaltree.pxi.in.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/intervaltree.pxi.in.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/join.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/join.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/join_func_helper.pxi.in.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/join_func_helper.pxi.in.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/join_helper.pxi.in.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/join_helper.pxi.in.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/khash.pxd.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/khash.pxd.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/lib.pxd.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/lib.pxd.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/lib.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/lib.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/missing.pxd.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/missing.pxd.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/missing.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/missing.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/parsers.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/parsers.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/properties.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/properties.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/reduction.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/reduction.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/reshape.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/reshape.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/reshape_helper.pxi.in.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/reshape_helper.pxi.in.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/skiplist.pxd.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/skiplist.pxd.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/skiplist.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/skiplist.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/sparse.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/sparse.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/sparse_op_helper.pxi.in.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/sparse_op_helper.pxi.in.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/src/inference.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/src/inference.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/src/util.pxd.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/src/util.pxd.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/testing.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/testing.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslib.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslib.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/ccalendar.pxd.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/ccalendar.pxd.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/ccalendar.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/ccalendar.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/conversion.pxd.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/conversion.pxd.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/conversion.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/conversion.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/fields.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/fields.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/frequencies.pxd.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/frequencies.pxd.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/frequencies.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/frequencies.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/nattype.pxd.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/nattype.pxd.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/nattype.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/nattype.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/np_datetime.pxd.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/np_datetime.pxd.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/np_datetime.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/np_datetime.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/offsets.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/offsets.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/parsing.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/parsing.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/period.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/period.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/resolution.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/resolution.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/strptime.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/strptime.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/timedeltas.pxd.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/timedeltas.pxd.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/timedeltas.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/timedeltas.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/timestamps.pxd.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/timestamps.pxd.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/timestamps.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/timestamps.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/timezones.pxd.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/timezones.pxd.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/timezones.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/tslibs/timezones.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/window.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/window.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/writers.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/_libs/writers.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/io/msgpack/_packer.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/io/msgpack/_packer.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/io/msgpack/_unpacker.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/io/msgpack/_unpacker.cpp: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/io/sas/sas.c: No such file or directory
ls: cannot access /home/travis/build/pandas-dev/pandas/pandas/io/sas/sas.cpp: No such file or directory
```

</details>

Any idea if what's up / if this is an issue?  Some of these moved recently, I think.

cc @jbrockmendel, @nparley 