Merge pull request #470 from mxiamxia/release-2.15.0

Update CHANGELOG for 2.15.0 release

Merge pull request #435 from wangzlei/release-2.14.0

Release commit for v2.14.0

Merge pull request #432 from jj22ee/release-2.13.1

Release commit for v2.13.1

Release commit for v2.13.0 (#421)

* Release commit for v2.13.0

Merge pull request #411 from aws/release-2-12-1

Release commit for v2.12.1

Merge pull request #386 from jj22ee/release-2.12.0

Release commit for v2.12.0

Release commit for v2.11.0 (#367)

Merge pull request #345 from wangzlei/master

Release commit for v2.10.0

Release commit for v2.9.0 (#318)

Release commit for v2.8.0 (#295)

* Updated CHANGELOG.rst

* Updated CHANGELOG.rst and version