Add automated create release branch workflow (#35)

* Add workflow to create a release branch from an automated script

* Merge workflows

.github/workflows/create-release-branch.yml

@@ -13,6 +13,10 @@ on:
         description: 'Partner version (e.g. ''~> 9.2.0'')'
         required: true
         default: '~> '
+  # Automated trigger from a job running on an external repo
+  repository_dispatch:
+    types:
+      - automated-create-release-branch
 
 env:
   GITHUB_TOKEN: ${{ secrets.GITHUBSERVICETOKEN }}
@@ -23,5 +27,5 @@ jobs:
     steps:
       - uses: chartboost/chartboost-mediation-ios-actions/create-adapter-release-branch@v1
         with:
-          adapter-version: ${{ inputs.adapter-version }}
-          partner-version: ${{ inputs.partner-version }}
+          adapter-version: ${{ inputs.adapter-version || github.event.client_payload.adapter-version }}
+          partner-version: ${{ inputs.partner-version || github.event.client_payload.partner-version }}