Style on page of bills list
update gitignore
Delete .lock and .DS_Store
update total amount format
add bill-details class to modal
Sort bills by criteria
remove default sort
Add mongoid
Add mongo configuration
Change Bill to be a mongo document and fix tests
Remove uneeded Bill methods and tests
Remove redis dependencies
Clean app.rb
Merge branch 'mongo'

Conflicts:
	Gemfile.lock
	model/bill.rb
Fix seed issue