make a member's user and team readonly
add team#full? and other supporting methods
validate a team max size
add MembersController, pending views
fix showing member's role
fix authorization in teams#edit
remove Summoner model, move summoner_name to User
user table on user#index
add Markdown renderer
create Tournament model, controller
fix flash message color
restructure assets into public/admin
add icon helper, show user's icon (admin?)