build(docker): add docker builder

gulpfile.js

@@ -23,12 +23,25 @@ exports.clean = function clean() {
     return gulp.src('target/*', {read: false}).pipe(gulpClean());
 };
 
-exports.generate = function generate()  {
-    return new Haxe().haxelib(['run', 'protohx', 'generate', 'protohx.json']).then(({stdout}) => {
-        if (stdout.indexOf('FAIL') > -1) {
-            throw stdout;
+exports.setup = function setup() {
+  const builder = Project.Builder.new(
+    client.config,
+    Project.Platform.ANDROID,
+    client.buildSystem,
+  );
+  return builder.prepare();
+};
+
+exports.generate = function generate() {
+  return exports.setup().then(() =>
+    new Haxe()
+      .haxelib(["run", "protohx", "generate", "protohx.json"])
+      .then(({ stdout }) => {
+        if (stdout.indexOf("FAIL") > -1) {
+          throw stdout;
         }
-    });
+      }),
+  );
 };
 
 /**