HipChat allows users to run their own private servers and to be able to
support those we must connect to the correct URL when using one of these
custom servers.
HipChat refers to their own product camel cased so we should do the
same. HipChat no longer recommends people use the deprecated v1 API so
switch to using the v2 API by default. hipchat-rb does not yet default
to v2 in any version so it must be specified.
Whenever a push with a lot of merges is made, the HipChat channel gets
overwhelmed. It is easy to loose everything else in all the GitLab
messages. It makes more sense to limit the number of commits shown.
The same problem happens with longer commit messages (like this one). It
will be useful to show only the subject of the commit message, not the
full one.