fix definitions/readme for #10

Author: PeterStaev

README.md

@@ -109,7 +109,7 @@ The Base64 encoded transaction receipt. You can use this to do additional verifi
 * **originalTransaction** - *Transaction*  
 This will be present only when restoring purchases and will contain the original transaction that purchased a given product. 
 
-* **developerPayload** - *string (Android only)*  
+* **developerPayload** - *string*  
 Custom data sent with `buyProduct`. 
 
 * **dataSignature** - *string (Android only)*  

transaction/transaction.d.ts

@@ -24,7 +24,7 @@ declare module "nativescript-purchase/transaction" {
         public transactionDate: Date;
         public transactionReceipt: string;
         public originalTransaction: Transaction;
-        public developerPayload: string; /* Android Only */
+        public developerPayload: string;
         public dataSignature: string; /* Android Only */
 
         constructor(nativeValue: any);