Merge branch 'release-0.15.0' into develop

* release-0.15.0:
  Bumping version to 0.15.0
Change readme from md to rst
Bumping version to 0.15.1
Merge branch 'release-0.15.1'

* release-0.15.1:
  Bumping version to 0.15.1
  Change readme from md to rst