feat(stacks): add the ability to specify env vars when deploying stacks (#1345)

app/helpers/formHelper.js

@@ -0,0 +1,18 @@
+angular.module('portainer.helpers')
+.factory('FormHelper', [function FormHelperFactory() {
+  'use strict';
+  var helper = {};
+
+  helper.removeInvalidEnvVars = function(env) {
+    for (var i = env.length - 1; i >= 0; i--) {
+      var envvar = env[i];
+      if (!envvar.value || !envvar.name) {
+        env.splice(i, 1);
+      }
+    }
+
+    return env;
+  };
+
+  return helper;
+}]);