Release tag for Appium 1.6.1-beta

Version 1.6.0

Third beta of 1.6.0

Beta 1 of 1.6.0

v1.5.3 release

Release version 1.5.1

Merge pull request appium#6344 from appium/isaac-changelog

Changelog for 1.5.1

tag 1.5.0 release

Beta 12 release of 1.5.0