Add "Run tests" button!

Still to do: The view that shows the test running.
Use Bootstrap's form styling

As per <http://getbootstrap.com/css/#forms>.

Note that bootstrap "highly recommends using the <button> element [as
opposed to <input type="submit">] whenever possible to ensure matching
cross-browser rendering".
Update Angular from v1.2.26 to v1.3.5

According to the download dialogue at <https://angularjs.org/>, 1.2.x is
the "legacy", bugfix-only branch; 1.3.x is the "latest stable branch".

For a new development it doesn't make sense to be using a legacy branch.
But specifically I want the "ng-touched" functionality[1] for form
validation.

1.3.x drops support for IE8, but I don't intend to support any version
of IE anyway (I can't handle the test & maintenance burden).

Everything seems to still work and all the tests (all 2 of them)
continue to pass.

[1] https://code.angularjs.org/1.3.5/docs/guide/forms#using-css-classes
Hook up angular's validation to bootstrap's css styles

As per <https://stackoverflow.com/questions/14348384/>.

I'm not ready yet to commit to the custom angular directives in that
stackoverflow link, though I concede that this commit's solution isn't
very DRY.

Note that specifying the <form>'s `name` attribute makes the form
available on the angular `$scope`.
More validation: Disable submit button, show help text

I use "ng-class" instead of "ng-show" because the latter uses
"display:hidden" which changes the layout as the help text
appears/disappears.
Provide default testjob name ("master")

So that you don't have to stop and *think* just to try out the system!
See also `TODO.md`.
css cleanup: Consolidate navbar padding rules into single rule

And remove a useless (and misspelled) comment -- after all, every one of
these rules is to override the bootstrap styles.
css fix: Remove 1px orange border left of logo in navbar

So that the hand of the stb-tester logo looks like it's coming out of
the edge of the window.
Extract polling for branch sha & tests into separate Service

This keeps the controller code shorter, and will allow me to inject a
mock "branchPoller" into the Controller for unit testing.
Rename "/automated" route to "/new-job"

I'm going to put the "test in progress" UI into a separate view &
controller, so the name "automated" is too general.

The menu item in the UI's navbar will still be the same one for both
views, and it still reads "Automated tests".
(IN PROGRESS) Add "/test-in-progress" view