feat(registries): add registry management (#930)

app/services/httpRequestHelper.js

@@ -0,0 +1,17 @@
+angular.module('portainer.services')
+.factory('HttpRequestHelper', [function HttpRequestHelper() {
+  'use strict';
+
+  var service = {};
+  var headers = {};
+
+  service.registryAuthenticationHeader = function() {
+    return headers.registryAuthentication;
+  };
+
+  service.setRegistryAuthenticationHeader = function(headerValue) {
+    headers.registryAuthentication = headerValue;
+  };
+
+  return service;
+}]);