TST: Test pivot with categorical data
TST: Test pivot with categorical data

closes #8860  closes #8731  closes #9534    Looks like the examples in
these issues pass in the master branch. Added test to confirm.

Author: Matt Roeschke <emailformattr@gmail.com>

Closes #14807 from mroeschke/test_pivot_categoricals and squashes the following commits:

b506083 [Matt Roeschke] TST: Test pivot with categorical data

gfyoung/pandas,kdebrab/pandas,winklerand/pandas,jmmease/pandas,jreback/pandas,zfrenchee/pandas,jmmease/pandas,jreback/pandas,cython-testbed/pandas,rs2/pandas,jmmease/pandas,toobaz/pandas,amolkahat/pandas,jmmease/pandas,Winand/pandas,jorisvandenbossche/pandas,linebp/pandas,zfrenchee/pandas,amolkahat/pandas,GuessWhoSamFoo/pandas,cbertinato/pandas,jorisvandenbossche/pandas,rs2/pandas,kdebrab/pandas,datapythonista/pandas,jreback/pandas,jorisvandenbossche/pandas,cython-testbed/pandas,Winand/pandas,datapythonista/pandas,dsm054/pandas,zfrenchee/pandas,Winand/pandas,TomAugspurger/pandas,winklerand/pandas,linebp/pandas,TomAugspurger/pandas,rs2/pandas,zfrenchee/pandas,louispotok/pandas,datapythonista/pandas,louispotok/pandas,gfyoung/pandas,cython-testbed/pandas,harisbal/pandas,harisbal/pandas,amolkahat/pandas,nmartensen/pandas,DGrady/pandas,cython-testbed/pandas,DGrady/pandas,TomAugspurger/pandas,jmmease/pandas,MJuddBooth/pandas,GuessWhoSamFoo/pandas,louispotok/pandas,harisbal/pandas,jorisvandenbossche/pandas,winklerand/pandas,cbertinato/pandas,kdebrab/pandas,gfyoung/pandas,cbertinato/pandas,louispotok/pandas,nmartensen/pandas,harisbal/pandas,zfrenchee/pandas,nmartensen/pandas,Winand/pandas,gfyoung/pandas,dsm054/pandas,MJuddBooth/pandas,GuessWhoSamFoo/pandas,louispotok/pandas,cbertinato/pandas,Winand/pandas,pratapvardhan/pandas,GuessWhoSamFoo/pandas,nmartensen/pandas,winklerand/pandas,dsm054/pandas,linebp/pandas,pandas-dev/pandas,winklerand/pandas,MJuddBooth/pandas,pandas-dev/pandas,nmartensen/pandas,pandas-dev/pandas,DGrady/pandas,amolkahat/pandas,jreback/pandas,linebp/pandas,dsm054/pandas,DGrady/pandas,amolkahat/pandas,MJuddBooth/pandas,toobaz/pandas,pratapvardhan/pandas,toobaz/pandas,cython-testbed/pandas,gfyoung/pandas,Winand/pandas,DGrady/pandas,datapythonista/pandas,pandas-dev/pandas,linebp/pandas,cbertinato/pandas,rs2/pandas,harisbal/pandas,pratapvardhan/pandas,toobaz/pandas,pratapvardhan/pandas,nmartensen/pandas,toobaz/pandas,GuessWhoSamFoo/pandas,linebp/pandas,MJuddBooth/pandas,kdebrab/pandas,pratapvardhan/pandas,TomAugspurger/pandas,jmmease/pandas,winklerand/pandas,DGrady/pandas,dsm054/pandas,jreback/pandas,kdebrab/pandas