Change Jenkins to use webhooks not polling

Author: paullinator

Jenkinsfile

@@ -75,12 +75,12 @@ pipeline {
   options {
     timestamps()
     skipDefaultCheckout true
-    overrideIndexTriggers false
+    overrideIndexTriggers true
     buildDiscarder logRotator(artifactDaysToKeepStr: '', artifactNumToKeepStr: '', daysToKeepStr: '7', numToKeepStr: '10')
     disableConcurrentBuilds()
   }
   triggers {
-    pollSCM('H/2 * * * *')
+    githubPush()
   }
   parameters {
     booleanParam(name: 'ANDROID_BUILD', defaultValue: true, description: 'Build an Android version')