Merge pull request #100 from coopdevs/error_if_email_reused

Error shown now when trying to create a new user with an existing email
renamed devise email .cat.html.erb files as .ca.html.erb instead
Merge pull request #101 from coopdevs/wrong_email_body_for_cat

renamed devise email .cat.html.erb files as .ca.html.erb instead
Added Vagrant support

fixed problems in seeds, added rubocop and haml-lint in dev area and finish corrections in bootstrap.sh script