add flow control files

flow/interfaces/mocha.js

@@ -0,0 +1,22 @@
+type TestFunction = ((done: () => void) => void | Promise<mixed>);
+
+declare var describe : {
+    (name:string, spec:() => void): void;
+    only(description:string, spec:() => void): void;
+    skip(description:string, spec:() => void): void;
+    timeout(ms:number): void;
+};
+
+declare var context : typeof describe;
+
+declare var it : {
+    (name:string, spec?:TestFunction): void;
+    only(description:string, spec:TestFunction): void;
+    skip(description:string, spec:TestFunction): void;
+    timeout(ms:number): void;
+};
+
+declare function before(method : TestFunction):void;
+declare function beforeEach(method : TestFunction):void;
+declare function after(method : TestFunction):void;
+declare function afterEach(method : TestFunction):void;

flow/interfaces/webpack.js

@@ -0,0 +1,7 @@
+declare var module : {
+  hot : {
+    accept(path:string, callback:() => void): void;
+  };
+};
+
+declare var require: any;

flow/stubs/url-loader.js

@@ -0,0 +1 @@
+export default '';