testArrayNumpyLabelled fails on Python 2.7.10
```
FAIL: testArrayNumpyLabelled (pandas.io.tests.test_json.test_ujson.NumpyJSONTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/ch/repo/pandas/.tox/py27/lib/python2.7/site-packages/pandas/io/tests/test_json/test_ujson.py", line 1141, in testArrayNumpyLabelled
    self.assertTrue((expectedvals == output[0]).all())
AssertionError: False is not true
-------------------- >> begin captured stdout << ---------------------
[[42 31]
 [24 99]
 [ 2 78]]
[[31 42]
 [99 24]
 [78  2]]

--------------------- >> end captured stdout << ----------------------
```

Order of dict elements seems to be non-deterministic for python2.7 versions as well.
