fix typo in README.md

schumannd · cbrevik · commit 03c74c96936b · 2018-12-19T11:57:06.000+01:00
diff --git a/README.md b/README.md
@@ -205,7 +205,7 @@ Call `InAppBilling.getSubscriptionTransactionDetails(productId)` and check the `
 
 ## Javascript API
 
-All methods returns a `Promise`.
+All methods return a `Promise`.
 
 ### open()
 
