Merge pull request activerecord-hackery#800 from mataki/fix-join-not-…

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Fix query of not_null with joining association

Version 1.8.2

Release 1.8.1

[skip ci]

Release 1.8.0

Version 1.7.0

Version 1.6.6

Version 1.6.5

Version 1.6.4

Version 1.6.3

Version 1.6.2