Fix Tournament slug

'slug' in the smash.gg API means all the string
"tournament/tournament-slug", but we only want the "tournament-slug"
part.

lokrez/smashgg.py

@@ -180,7 +180,7 @@ class Tournament():
             ):
         self.id           = id
         self.name         = name
-        self.slug         = slug
+        self.slug         = slug.split("/")[-1]
         self.startAt      = startAt
         self.numEntrants  = numEntrants
         self.venueAddress = venueAddress