Remove course delete functionality
Remove course delete functionality

Was partly implemented in client but not in server. We can live without
it. Part of #215

MaBreaker/rg2,Maprunner/rg2,LukeWoodward/rg2,MaBreaker/rg2,MaBreaker/rg2,LukeWoodward/rg2,LukeWoodward/rg2,Maprunner/rg2,Maprunner/rg2