Namespace model name translations (fixes #58)

* Replace "account" with "pageflow/account" and so on in
  activerecord.yml.
* Also supply aliases for non namespace variant.
  ActiveAdmin skips module names since we register admins with
  `as: "Account"` option to get routing right.
Make jQuery gem dependencies more specific

ActiveAdmin only depends on jquery-ui-rail >= 4.0 but breaks with
version 5.0.
update Gemfile.lock
Merge pull request #66 from tf/model-name-translations

Namespace model name translations (fixes #58)
Merge pull request #67 from tf/jquery-rails-version

Make jQuery gem dependencies more specific (fixes #63)