Add workflow triggering Jenkins build on tag (#45)

* Add workflow triggering Jenkins build on tag

When a new release is published in this repository, this action will run and trigger a build of the tag on Jenkins.

* Use DelphesO2 release naming scheme

Author: TimoWilken

.github/workflows/release.yml

@@ -0,0 +1,27 @@
+name: Release
+
+on:
+  release:
+    types: [published]
+  
+jobs:
+  build_release:
+    runs-on: ubuntu-18.04
+    steps:
+    - name: Install Kerberos
+      run: |
+        sudo apt-get update
+        sudo DEBIAN_FRONTEND=noninteractive apt-get install -y krb5-user
+        cat << \EOF > krb5.conf
+        ${{secrets.KRB5CONF}}
+        EOF
+        grep rdns krb5.conf
+        sudo mv -f krb5.conf /etc/krb5.conf
+        
+    - name: Trigger release in jenkins
+      run: |
+       echo ${{github.event.release.tag_name}} | grep -e 'v20[0-9][0-9][0-1][0-9][0-9][0-9]'
+       echo ${{secrets.JENKINS_BOT_PASS}} | kinit ${{secrets.PRINCIPAL}}
+       curl -X POST -k --negotiate -u : ${{secrets.API_URL}} -H 'Content-Type: application/x-www-form-urlencoded' -d 'DELPHESO2_TAG=${{github.event.release.tag_name}}'
+       klist
+       kdestroy