vrfs-916: added following? method

ruby/lib/jam_ruby/models/user.rb

@@ -261,6 +261,10 @@ module JamRuby
       return self.band_likes.size
     end
 
+    def following?(user)
+      self.followings.exists?(user)
+    end
+
     def follower_count
       return self.followers.size
     end