Convert two tests to almost_equal variant
Convert two tests to almost_equal variant

Prevent the tests below from failing with very close values:

    ======================================================================
    FAIL: seaborn.tests.test_categorical.TestCategoricalStatPlotter.test_nested_stats_with_missing_data
    ----------------------------------------------------------------------
    [...]
    Items are not equal:
     ACTUAL: -0.018721526986487352
     DESIRED: -0.018721526986487342

    ======================================================================
    FAIL: seaborn.tests.test_categorical.TestCategoricalStatPlotter.test_single_layer_stats_with_missing_data
    ----------------------------------------------------------------------
    [...]
    AssertionError:
    Items are not equal:
     ACTUAL: 0.082012970747837352
     DESIRED: 0.08201297074783731

mclevey/seaborn,dhimmel/seaborn,huongttlan/seaborn,nileracecrew/seaborn,tim777z/seaborn,ashhher3/seaborn,oesteban/seaborn,lypzln/seaborn,mwaskom/seaborn,dimarkov/seaborn,mwaskom/seaborn,lukauskas/seaborn,arokem/seaborn,sinhrks/seaborn,q1ang/seaborn,JWarmenhoven/seaborn,petebachant/seaborn,Lx37/seaborn,phobson/seaborn,wrobstory/seaborn,bsipocz/seaborn,mia1rab/seaborn,muku42/seaborn,olgabot/seaborn,sauliusl/seaborn,arokem/seaborn,uhjish/seaborn,gef756/seaborn,phobson/seaborn,lukauskas/seaborn,clarkfitzg/seaborn,drewokane/seaborn,anntzer/seaborn,anntzer/seaborn,jat255/seaborn