Update README.

Author: Gary Gregory

README.md

@@ -81,7 +81,7 @@ There are some guidelines which will make applying PRs easier for us:
 + No tabs! Please use spaces for indentation.
 + Respect the code style.
 + Create minimal diffs - disable on save actions like reformat source code or organize imports. If you feel the source code should be reformatted create a separate PR for this change.
-+ Provide JUnit tests for your changes and make sure your changes don't break any existing tests by running ```mvn clean test```.
++ Provide JUnit tests for your changes and make sure your changes don't break any existing tests by running ```mvn```.
 
 If you plan to contribute on a regular basis, please consider filing a [contributor license agreement](https://www.apache.org/licenses/#clas).
 You can learn more about contributing via GitHub in our [contribution guidelines](CONTRIBUTING.md).