Channel owner can download a CSV with the subscribers data [Fix #56088536]
locked postgres-copy version to use last version compatible with Rails 3.2
Merge branch 'channel_statistics' of https://github.com/devton/catarse into channel_statistics
changed subscribers report to use postgres-copy instead of CSV.
added user url to csv
added spec for channel report
merged master
just cleaning up unnecessary FactoryGirl constant
moved channel_spec and removed unnecessary FactoryGirl const
added subscriber_reports association
created a database view exclusive for the channel subscribers report
renamed SubscribersController to SubscribersReports controller and removed unnecessary code to report generation, now this model uses a specific database view (hence the renaming).
begin_of_association_chain should be private
tidying up a bit the view
removed unnecessary spaces
fixed failing spec
Merge pull request #302 from diogob/channel_statistics

changed subscribers report to use postgres-copy instead of CSV.