Update link to example page for Relay GraphQL Mutations
Summary: Closes
@@ -264,4 +264,4 @@ Rolls back an optimistic mutation.
## See also
-A number of more detailed usage examples can be found [in the test suite](https://github.com/facebook/relay/blob/master/src/mutation/__tests__/RelayGraphQLMutation-test.js).
+A number of more detailed usage examples can be found [in the test suite](https://github.com/facebook/relay/blob/master/packages/react-relay/classic/mutation/__tests__/RelayGraphQLMutation-test.js).
