[tests] configure maven surefire so it runs test files in random order

[marcdumais-work]

Feature Description:

Recently it was discovered that some tests were changing e.g. global properties, and that if the test files were run in a different order, some tests would fail.

If the various test files were run in a random order, it would make it more likely to detect issues between them, e.g. one affecting the other(s). ATM the order is unspecified but seems consistent on a given machine.

This can be done like so (root pom.xml):

        <plugin>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>3.0.0</version>
          <configuration>
            <runOrder>random</runOrder>
          </configuration>
        </plugin>