Added weekly users ranking view

[#71]
Added weekly user support counting method

[#71]
Added sorting by week support count method

[#71]
Added weekly points decorator

[#71]
Exposed sorted weekly users

[#71]
Edited week user ranking view

[#74]
Added supports_from_n_days scope

[#74]
Edited method to count supports from n days

[#74]
Added specs for user and support model
Edited sorting method with SQL request
Edited supports - count from the beginning of week
Edited names to be more precise
Fixed support scope
Edited this week best users sql query
Deleted supports weekly count
Minor changes in this week best users method
Added scope with users sorted by points and name
Merge branch 'master' into add_best_week_supporters
align lines, use Time.zone.now
cleanup