Max announcements per hour

[veelenga]

I'm afraid we are open for some spamming. Attacker can easily create lots of dummy announcements and spam twitter/rss and our list of announcements on the web.

The idea is to set a max limit of created announcements per hour which can a specific user do.

TODOs:

• Create a before_action for AnnouncementController#create which will:

  • Find a number of announcements created by current_user within last hour
  • If that number exceeds ENV["MAX_ANNS_PER_HOUR"], just redirect to / for now.
  • Otherwise, user is able to proceed.
  • Add tests

• Ignore this feature if ENV["MAX_ANNS_PER_HOUR"] is not set or is 0.

• Add MAX_ANNS_PER_HOUR to the list of used env variables in Readme.