test_expand_user failure in 0.17.0
``` python
======================================================================
FAIL: test_expand_user (pandas.io.tests.test_common.TestCommonIOCapabilities)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/var/tmp/portage/dev-python/pandas-0.17.0/work/pandas-0.17.0-python3_4/lib/pandas/io/tests/test_common.py", line 20, in test_expand_user
    self.assertTrue(isabs(expanded_name))
AssertionError: False is not true
```

``` python
INSTALLED VERSIONS
------------------
commit: None
python: 3.4.3.final.0
python-bits: 64
OS: Linux
OS-release: 4.1.8-lh
machine: x86_64
processor: Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz
byteorder: little
LC_ALL: None
LANG: en_GB.utf8

pandas: 0.17.0
nose: 1.3.7
Cython: 0.23.3
numpy: 1.9.3
scipy: 0.16.0
statsmodels: 0.6.1
IPython: 4.0.0
sphinx: 1.3.1
patsy: 0.4.0
dateutil: 2.4.2
pytz: 2015.6
bottleneck: 1.0.0
tables: 3.2.2
numexpr: 2.4.4
matplotlib: 1.4.3
openpyxl: 2.2.6
xlrd: 0.9.4
xlwt: 1.0.0
xlsxwriter: 0.7.4
lxml: 3.4.4
bs4: 4.4.1
html5lib: 0.9999999
httplib2: 0.9.2
apiclient: None
sqlalchemy: 1.0.8
pymysql: 0.6.6.None
psycopg2: 2.6.1 (dt dec pq3 ext lo64)
```

happens the same way with python3.3. Py2 untested yet.
