updated contributing.md

Author: errc-lee

CONTRIBUTING.md

@@ -15,7 +15,7 @@ All code changes happen through Github Pull Requests and we actively welcome the
 5. Ensure the test suite passes and on Travis CI as well.
 6. Make sure your code lints.
 7. Push to the branch (git push origin [my-new-feature])
-8. Issue that pull request! Specify what you changed in details when you are doing pull request.
+8. Issue that pull request! Specify what you changed in details when you are doing pull request & squash all commits.
 
 Note: Any contributions you make will be under the MIT Software License and your submissions are understood to be under the same that covers the project. Please reach out to the team if you have any questions.