Merge pull request leancloud#234 from aisk/master

docs: bump version

Merge pull request leancloud#231 from aisk/master

docs: release 1.6.4

docs: release 1.6.3 (leancloud#216)

docs: release 1.6.2 (leancloud#210)

Merge pull request leancloud#204 from aisk/master

doc: release 1.6.1

feat: release 1.6.0

feat: release 1.5.1

feat: release 1.5.0

Merge pull request leancloud#174 from aisk/master

fix: can't install in leanengine

docs: release 1.4.2