Cache delete items

I can now delete things from the cache in addition to adding things.

libsaria/path/cache.py

@@ -35,6 +35,11 @@ class CacheObject:
 		else:
 			return path
 
+	def delete(self, key):
+		path = join(self.path, key)
+		if exists(path):
+			rm(path)
+
 class Cache:
 	def keys(self):
 		return ls(CACHE_DIR)