removed wrong type of Target.__init__ path arg from doc

Author: kmaork

luigi/target.py

@@ -213,7 +213,7 @@ def __init__(self, path):
         """
         Initializes a FileSystemTarget instance.
 
-        :param str path: the path associated with this FileSystemTarget.
+        :param path: the path associated with this FileSystemTarget.
         """
         # cast to str to allow path to be objects like pathlib.PosixPath and py._path.local.LocalPath
         self.path = str(path)