The trusty apache2 charm fails automated testing

In an effort to improve quality, we are testing all charms in an automated process.

According to the latest test results by charm http://reports.vapour.ws/charm-tests-by-charm this charm is failing automated testing.

The automated testing tool runs the `make lint`, `make test` targets, and runs the tests in the tests/ directory. The automated report can be found here:
http://reports.vapour.ws/charm-tests/charm-bundle-test-455-results

According to the report the `make lint` and 'make test' targets fail with errors similar to the precise/apache2 charm.

I have written a simple deployment amulet test that is in the review queue. The amulet tests pass but the `make test` target still fails with the same error. That output can be found here:

http://reports.vapour.ws/charm-tests/charm-bundle-test-10634-results

The `make test` target failure still needs to be addressed. The error output is:

FAIL: tests.test_cert.CertTests.test_is_selfsigned_cert_stale_private_address_changed
----------------------------------------------------------------------
_StringException: Traceback (most recent call last):
  File "/var/lib/jenkins/workspace/charm-bundle-test/tmpyTrz7b/apache2/.venv/local/lib/python2.7/site-packages/mock.py", line 1201, in patched
    return func(*args, **keywargs)
  File "/var/lib/jenkins/workspace/charm-bundle-test/tmpyTrz7b/apache2/hooks/tests/test_cert.py", line 95, in test_is_selfsigned_cert_stale_private_address_changed
    hooks.is_selfsigned_cert_stale(config, cert_file, key_file))
  File "/var/lib/jenkins/workspace/charm-bundle-test/tmpyTrz7b/apache2/.venv/local/lib/python2.7/site-packages/unittest2/case.py", line 678, in assertTrue
    raise self.failureException(msg)
AssertionError: False is not true