Update path.py

Fix for later versions of Python with "ImportError: cannot import name 'MutableSequence' from 'collections'' error.

Author: MattStedman

svgpath/path.py

@@ -1,6 +1,6 @@
 from __future__ import division
 from math import sqrt, cos, sin, acos, degrees, radians, log
-from collections import MutableSequence
+from collections.abc import MutableSequence
 
 # This file contains classes for the different types of SVG path segments as
 # well as a Path object that contains a sequence of path segments.