Common push incantation

Jenkinsfile

@@ -57,9 +57,9 @@ node {
 
   stage 'SHIP: Base'
 
-    docker.withRegistry('https://registry.hub.docker.com/', 'dockerhub-bigfleet') {
-      def baseImg = docker.build('bigfleet/centos7base')
-      baseImg.push('latest')
+    docker.withRegistry('https://registry.hub.docker.com/',   "dockerhub-$maintainer") {
+      def baseImg = docker.build("$maintainer/$imagename")
+      baseImg.push("$tag")
     }
 }