link to pypi page

Fixes #19

Author: astraw

README.rst

@@ -70,6 +70,8 @@ Meta-data
  * Contact: [email protected]
  * Homepage: http://github.com/astraw/svg_stack
  * Issue tracker: http://github.com/astraw/svg_stack/issues
+ * pypi link: https://pypi.org/project/svg-stack/
+
 
 Command-line usage
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