Merge branch 'hotfix/0.1.21'

* hotfix/0.1.21:
  use latest version of grunt
  bump version to 0.1.21
  bump version to 0.1.20
bump version to 0.1.22
Merge branch 'hotfix/0.1.22' into develop

* hotfix/0.1.22:
  bump version to 0.1.22