BUG: Groupby.get_group doesnt work with TimeGrouper
CLN: drop internals._invert_reordering in favour of lib.get_reverse_indexer
Merge pull request #6988 from immerrr/refactor-blockmanager

CLN: drop internals._invert_reordering in favour of lib.get_reverse_indexer
DOC: fix some doc build warnings
TST: fix checking for less_precise in floats
Merge pull request #6989 from jorisvandenbossche/doc-fixes2

DOC: fix some doc build warnings
BLD: move PANDAS_TESTING_MODE env variable to .travis_yml
BLD: remove scatterci references
Merge pull request #6990 from jreback/less_precise

TST: fix checking for less_precise in floats
Merge pull request #6914 from sinhrks/getgroup

BUG: GroupBy.get_group doesnt work with TimeGrouper