Using postField for SyncSso payload
Fixing additionalParameters for CreateCategory operation
Adding deleteGroup operation
Moving model to base config
Updating to Discourse\Sso 1.2.0
Setting version to 0.3.0
Merge branch 'release/v0.3.0'

* release/v0.3.0:
  Setting version to 0.3.0
  Updating to Discourse\Sso 1.2.0
  Moving model to base config
  Adding deleteGroup operation
  Fixing additionalParameters for CreateCategory operation
  Using postField for SyncSso payload