Add TAP output to test.tap for CI consumption

Jenkins is configured to read [TAP](https://en.wikipedia.org/wiki/Test_Anything_Protocol) files, so we can present more detailed information about test failures in the UI for the [hammer tests](http://ci.theforeman.org/job/systest_foreman_hammer_nightly/).

Example generated output: http://paste.fedoraproject.org/137712/20733441/raw/
Example job view (click the test result links): http://ci.theforeman.org/job/tapstest/5/