feature : forces index_type comparaison when asserting that one Dataf…
Until now, when comparing if 2 Dataframes were like each other, reindexing occurred as a inner mechanism. It turns out, if the two indexes are not of the same type, one of the Dataframe was emptied and the assertion always failed.
This fix forces the comparison of the index types if this specific case.

Example of code that will work with this fix
```
import pandas as pd

left = pd.DataFrame(data=[['20181130', 3, 7.45678, '20181129'], ['20181130', 12, 37.45678, '20181129']],
                    columns=["tomorrow", "one", "two", "today"])

left.today = left.today.astype('datetime64')

right = left.copy()
right.iloc[0, :], right.iloc[1, :] = right.iloc[1, :], right.iloc[0, :]
right.one = right.one.astype(str)

right = right.set_index("one")
left = left.set_index("one")

print(left)
print(right)

pd.testing.assert_frame_equal(left, right, check_like=True)
```