Switch to admin gem.
Switch to using govuk_admin_template layout.
Update application views to Bootstrap 3.

* Use grid classes
* Default button class
* Glyphicons
* Modal wrapper divs

Also add a background color for new application form to improve readability.
Remove unused autocompletion script.
Add vendored typeahead script.

This was removed from core Bootstrap in version 3.
Upgrade datetimepicker library.

Replace vendored version with gem that has been rewritten for Bootstrap 3.
Bump admin gem.
Use input grid helpers rather than wrapper divs.
Add typeahead CSS.
Add JsDatetimePicker input class.

Adds "wrapper_options" parameter to pass required HTML attributes to the
input_group div to allow the JS datetimepicker to work correctly.
Convert new deployments form to Boostrap 3.

* Switch to semantic_form helper (except for datetimepicker field, as the
formtastic-bootstrap gem does not support adding the relevant classes in the
correct places).
* Make datepicker and typeahead work.
Convert releases form to bootstrap 3.

* Replace input-xxlarge classes with new col helper classes.
* Add hr to separate action buttons now that form-actions no longer exists.
* Add datepicker and typeahead JS for consistency with deployment form.
Use button styles more consistently.
Fix tests.

* Insert date as text now that deploy_at uses datepicker.
* Deal with case when user is not logged in.
Use Bootstrap styles on activity list.

Remove specific overrides.
Tweak application table styles.

* Add header style, align sorting arrows in centre.
* More spacing: remove table-condensed style, split deployment details to move
  date/time to next line.
* Use 'plus' glyphicon for 'add deployment'.
Add lead paragraph and table header styles.
Merge pull request #64 from alphagov/admin_gem

Use admin gem and Bootstrap 3 styles.