axios: allow transformRequest to take a list

axios/axios-tests.ts

@@ -16,3 +16,13 @@ axios<Repository>({
     method: HttpMethod[HttpMethod.GET],
     headers: {},
 }).then(r => console.log("ID:" + r.data.id + " Name: " + r.data.name));
+
+axios.post("http://example.com/", {}, {
+    transformRequest: (data: any) => data
+});
+
+axios.post("http://example.com/", {}, {
+    transformRequest: [
+        (data: any) => data
+    ]
+});

axios/axios.d.ts

@@ -17,7 +17,7 @@ declare module Axios {
      * This is only applicable for request methods 'PUT', 'POST', and 'PATCH'
      * The last function in the array must return a string or an ArrayBuffer
      */
-    transformRequest?: <U>(data:T) => U;
+    transformRequest?: (<U>(data:T) => U)|[<U>(data:T) => U];
 
     /**
      * change the response data to be made before it is passed to then/catch