add constances to represent state of status codes for task and treasure models
fix treasure's price validation to only validate for ON_SALE create only
update pirate index view to display different types of treasures: on_sale, bought, and wishlist
update user helpers to use methods from user model rather than redefining it
WIP updating views for tasks
WIP updating view
Merge branch 'pirate_buying' of https://github.com/DexterV/daddyshop into travis_UI
Add task lists view to Pirates, WIP for Captains