1. Modify the component to support a callback for every key press in the
filter. We need this so we can update the "Create: <branch_name"
label.
2. Modify the component to use `$(<selector>).first().click()` instead
of `$(selector)[0].click()`, because the latter is non-standard, and
doesn't work in PhantomJS.
1. Doesn't seem like there's an easy way to do this for the actual
branch protection, since we'd have to test an actual `git push`.
2. Testing branch creation the web UI is also not straightforward,
since the factory repo doesn't have any hooks, and so access checks
at the `gitlab-shell` level aren't run.
