Now that the Zuul web server and database are both required, provide
a consistent user experience by always reporting the build page.
This means that success-url and failure-url are no longer useful,
so remove them.
Update the quick-start to reflect that the build page is always
reported.
Change-Id: I4ff108df3917c9b6f44e2f5b0ccc4a7adbda1677