Add admin client JS/LESS to extension stub

stubs/extension/js/admin/Gulpfile.js

@@ -0,0 +1,7 @@
+var gulp = require('flarum-gulp');
+
+gulp({
+  modules: {
+    '{{name}}': 'src/**/*.js'
+  }
+});

stubs/extension/js/admin/package.json

@@ -0,0 +1,7 @@
+{
+  "private": true,
+  "devDependencies": {
+    "gulp": "^3.8.11",
+    "flarum-gulp": "git+https://github.com/flarum/gulp.git"
+  }
+}

stubs/extension/js/admin/src/main.js

@@ -0,0 +1,6 @@
+import { extend } from 'flarum/extend';
+import app from 'flarum/app';
+
+app.initializers.add('{{name}}', () => {
+  // TODO
+});

stubs/extension/js/forum/Gulpfile.js

@@ -1,5 +1,7 @@
 var gulp = require('flarum-gulp');
 
 gulp({
-  modulePrefix: '{{name}}'
+  modules: {
+    '{{name}}': 'src/**/*.js'
+  }
 });

stubs/extension/js/forum/src/main.js

@@ -1,6 +1,6 @@
 import { extend } from 'flarum/extend';
 import app from 'flarum/app';
 
-app.initializers.add('{{name}}', app => {
+app.initializers.add('{{name}}', () => {
   // TODO
 });