Transpose method not working with pandas dataframes
Under Ubuntu 16, I am getting the following:

```
>>> import pandas as pd
>>> import numpy as np
>>> a = np.array([[1, 2], [3, 4]])
>>> a = pd.DataFrame(a)
>>> a
   0  1
0  1  2
1  3  4
>>> np.transpose(a)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "....../anaconda2/lib/python2.7/site-packages/numpy/core/fromnumeric.py", line 551, in transpose
    return transpose(axes)
TypeError: transpose() takes exactly 1 argument (2 given)
>>> a.T
   0  1
0  1  3
1  2  4
>>> np.transpose(a.as_matrix())
array([[1, 3],
       [2, 4]])
```
