Ansible launcher: fix check of ansible exit code
Ansible launcher: fix check of ansible exit code

runAnsible* only returns a boolean -- success or failure, but we
were assuming it returned an exit code.  Make runAnsible* tristate
so that it returns success, failure, or indeterminate and move the
exit code comparison closer to where ansible actually exits.

Change-Id: I824681787f86c46b52817d473c37640ad19ee155

gooddata/zuul,wikimedia/integration-zuul,gooddata/zuul,wikimedia/integration-zuul,wikimedia/integration-zuul,wikimedia/integration-zuul,gooddata/zuul,gooddata/zuul,gooddata/zuul