Make logger available during tests

If any tests exercise code paths that emit logs, a warning is
displayed:

  No handlers could be found for logger "jenkins_jobs.modules.NAME"

Set up a logger with default configuration in the base test
class.  Now any logs will be displayed on the console.

Change-Id: Ib36afd5d96ff8e7fed110b6bedb6e281aac584f8
Merge "Make logger available during tests"