Fix path param of Language.__init__ always being ignored

There was an explicitly-declared `path` keyword argument, so 'path'
would never be present in `**overrides`. This line just overwrote
any manually-specified value the user might've passed to the `path`
parameter.

spacy/language.py

@@ -248,7 +248,6 @@ def train(cls, path, gold_tuples, *configs):
     def __init__(self, path=True, **overrides):
         if 'data_dir' in overrides and 'path' not in overrides:
             raise ValueError("The argument 'data_dir' has been renamed to 'path'")
-        path = overrides.get('path', True)
         if isinstance(path, basestring):
             path = pathlib.Path(path)
         if path is True: