BUG: fix isnull for 0d object arrays
Merge pull request #7176 from shoyer/isnull-0d-object-array

BUG: fix isnull for 0d object arrays
CLN: Deprecation of assert_

#7131: Fix two instances of assertEquals that naive grepping did not find
Merge pull request #7182 from bwignall/issue7131_assertEquals

CLN: Deprecation of assert_
DOC: some doc build fixes
Merge pull request #7185 from jorisvandenbossche/doc-fixes3

DOC: some doc build fixes
ENH: lookup global constants correctly in query/eval