chore(travis): remove test:docgen task from build

The task was removed by an earlier commit, and executing it breaks TravisCI builds. It may be
replaced at a later date.
chore(grunt): grunt should error when doc generation grunt errors
chore(doc-gen): fix navGroup hrefs
chore(doc-gen): only output info (and more severe) log messages
docs(guide): remove unnecessary "Developer Guide: " from @names
EXPERIMENT