PULL_REQUEST_TEMPLATE

*Thank you for submitting a pull request, your contributions are greatly appreciated!*

Please include a summary of the change and which issue is fixed. Please also include relevant motivation and context. List any dependencies that are required for this change.

Please make sure you've run the test scheme and all the tests pass. If your changes affect existing tests please make sure to update the tests as well.

Below is the PR naming guidelines we follow:

https://github.com/mozilla-mobile/firefox-ios/wiki/Pull-Request-Naming-Guide