Remove a redundant ng-class

Signed-off-by: Lance Chen <cyen0312@gmail.com>
Replace json file backend with firebase

Signed-off-by: Lance Chen <cyen0312@gmail.com>
Change choice index from string to integer

Signed-off-by: Lance Chen <cyen0312@gmail.com>
Sort legislator list by party

Signed-off-by: Lance Chen <cyen0312@gmail.com>