Media sync (#197)

* Fix: error 405 for media.sync when request with POST

* Media: create setter for instagram

Author: sviande

media.go

@@ -677,6 +677,11 @@ func (media *FeedMedia) instagram() *Instagram {
 	return media.inst
 }
 
+// SetInstagram set instagram
+func (media *FeedMedia) SetInstagram(inst *Instagram) {
+	media.inst = inst
+}
+
 // SetID sets media ID
 // this value can be int64 or string
 func (media *FeedMedia) SetID(id interface{}) {
@@ -701,7 +706,7 @@ func (media *FeedMedia) Sync() error {
 		&reqOptions{
 			Endpoint: fmt.Sprintf(urlMediaInfo, id),
 			Query:    generateSignature(data),
-			IsPost:   true,
+			IsPost:   false,
 		},
 	)
 	if err != nil {