Remove admin controllers and specs close #77

This is part of #47
Remove admin views #47
Add neighborly-admin to gemfile
Remove admin routes and mount neighborly-admin
Remove admin policy
Remove admin JS close #79
Remove admin translations
Remove admin menu
Add channels admin menu
Add channels admin translactions
Change admin url
Move admin styles close #80
Update neighborly-admin version
Remove unnused view
Remove best in place from channels admin
Update neighborly-admin gem version
Merge pull request #47 from neighborly/jl-remove-admin

Move admin to a Rails Engine