Merge pull request #122 from haysmike/haysmike/fix-access-token-docs

Fix docs for Github Personal Access Token

CONTRIBUTING.md

@@ -140,7 +140,7 @@ cargo install cargo-ndk
 
    ```
    gpr.user=username
-   gpr.key=key
+   gpr.token=token
    ```
 5. Open the Gradle workspace ('android/') in Android Studio.
    Gradle builds automatically ensure the core is built,