Use window.location.origin for sharing url.
Remove require outside of task

In production the jasmine gem is not installed so this raise and exception.
Merge pull request #77 from codeforamerica/remove-jasmine-require

Remove require outside of task
WIP
Use built in mass-assignment protection for sequel models
Add map remix backend
Remove activesupport

Not using Hash#slice
Hookup remix button.
Refactor #remix
Track which map a remix came from
Don't allow remixed_from_id to be mass-assigned
Move remix logic to router.
Use Remix, Remix 2, Remix 3 naming strategy.
Remove renaming from front-end.
Track the remix count and nth remix values for a map

* remix_count - integer representing the number of times a given map
  has been remixed. Equivalent to the result of the following query:
  `SELECT count(*) AS "count" FROM "maps" WHERE ("remixed_from_id" = 1) LIMIT 1`
* nth_remix - integer representing the order in which a remix occured.
  The first remix of map A will have an nth_remix value of 1, the
  second remix of map A will have an nth_remix value of 2, and so on