Use new govuk_admin_template gem
Apply govuk_admin_template to transition

* Delete styles now coming from gem
  * Put back some styles not appropriate for gem
* Setup content blocks for main template
* Remove bootstrap from gemfile
Put back tag styles

* Remove from base and put into separate stylesheet
Use javascript framework from admin gem

* Delete modules and framework files and specs that have been moved to
gem
* Rename GOVUK to GOVUKAdmin for existing modules
* Leave non-modules as GOVUK for now
Include libraries within jasmine tests

* Specify compiled gem javascript file so that bootstrap and jquery,
along with framework are available for tests