CLN: Deprecation of assertEquals
#7131: s/self.assertEquals(/self.assertEqual(

Note: This was a straight search-and-replace.
 FYI: if you want to see what's remaining on 3.4, copy this line: https://github.com/pydata/pandas/blob/master/.travis.yml#L79

to both of the 3.4 entries in `.travis.yml` (it STILL may be too much output but maybe ok)
 thanks!
