Add config for 'arc lint' and 'arc unit'.
Add config for 'arc lint' and 'arc unit'.

Summary: Add workaround for test frameworks that overwrite each other files.

Test Plan:
Download https://oss.sonatype.org/content/repositories/releases/org/scalastyle/scalastyle_2.11/0.6.0/scalastyle_2.11-0.6.0-batch.jar
and plaze it in the root directory to met-api.

'arc lint' and 'arc unit' should no work.

Reviewers: michaeloa

Reviewed By: michaeloa

Differential Revision: https://phab.met.no/D109