Rename confusing variable
Rename confusing variable

@slug was being used for both 'slug' and 'application name' arguments.

It's used in only one place as 'slug' but in several places as 'application name', so I've renamed it to 'application_name'.

alphagov/whitehall,robinwhittleton/whitehall,ggoral/whitehall,alphagov/whitehall,alphagov/whitehall,ggoral/whitehall,askl56/whitehall,robinwhittleton/whitehall,YOTOV-LIMITED/whitehall,hotvulcan/whitehall,hotvulcan/whitehall,alphagov/whitehall,hotvulcan/whitehall,robinwhittleton/whitehall,YOTOV-LIMITED/whitehall,robinwhittleton/whitehall,askl56/whitehall,ggoral/whitehall,hotvulcan/whitehall,YOTOV-LIMITED/whitehall,askl56/whitehall,ggoral/whitehall,YOTOV-LIMITED/whitehall,askl56/whitehall