Add cookies property to the InjectOptions interface type definition (#74)

* Add cookies property to the InjectOptions interface type definition

* Add type unit test to InjectOptions cookies property

Author: gyszalai

index.d.ts

@@ -57,6 +57,7 @@ declare namespace LightMyRequest {
     validate?: boolean
     payload?: InjectPayload
     server?: http.Server
+    cookies?: { [k: string]: string }
   }
 
   interface Request extends stream.Readable {

test/index.test-d.ts

@@ -22,6 +22,14 @@ inject(dispatch, { method: 'get', url: '/' }, (err, res) => {
   console.log(res.cookies)
 })
 
+inject(dispatch, { method: 'get', url: '/', cookies: { name1: 'value1', value2: 'value2' } }, (err, res) => {
+  expectType<Error>(err)
+  expectType<Response>(res)
+  console.log(res.payload)
+  expectType<Function>(res.json)
+  console.log(res.cookies)
+})
+
 inject(dispatch)
   .get('/')
   .end((err, res) => {