Adding contribution HOWTO
Merge branch 'dev' of github.com:MSOpenTech/azure-activedirectory-library-for-ios into dev

# By Boris Vidolov
# Via Boris Vidolov (2) and Omer Cansizoglu (1)
* 'dev' of github.com:MSOpenTech/azure-activedirectory-library-for-ios:
  More logging (code reviewed by Omer in my office)
  Test commit to trigger build.
  Fix a bug with not returning the multi-refresh token.
  Small text fix in one of the tests.
  Fixing a weird typo.
  Fix the issue with changing the keychain group