Add Jenkins job for auto-updates

jenkins_jobs.groovy

@@ -0,0 +1,46 @@
+// Jenkins build jobs for babel-standalone
+
+job('babel-standalone-update') {
+  description 'Updates babel-standalone to the latest version of Babel'
+  label 'powershell'
+  scm {
+    git {
+      branch 'master'
+      remote {
+        github 'babel/babel-standalone', 'ssh'
+      }
+      extensions {
+        // Required so we can commit to master
+        // http://stackoverflow.com/a/29786580/210370
+        localBranch 'master'
+      }
+    }
+  }
+  triggers {
+    urlTrigger {
+      cron 'H/15 * * * *'
+      url('https://babel-standalone.dan.cx/latest-babel-version') {
+        inspection 'change'
+      }
+    }
+  }
+
+  wrappers {
+    credentialsBinding {
+      string 'GITHUB_TOKEN', 'BABEL_STANDALONE_GITHUB_TOKEN'
+    }
+  }
+  steps {
+    powerShell '''
+      $Env:GITHUB_USER = 'babel'
+      $Env:GITHUB_REPO = 'babel-standalone'
+      .\\scripts\\update.ps1
+    '''
+  }
+  publishers {
+    git {
+      branch 'origin', 'master'
+      pushOnlyIfSuccess
+    }
+  }
+}