Specify the README format for pipy

Set the format to markdown because the default is rst

Author: simon-begin

setup.cfg

@@ -6,6 +6,7 @@ author-email = [email protected]
 summary = Friendly python client to James D. Bloom's awesome MockServer
 description-file =
     README.md
+long_description_content_type = text/markdown
 classifier =
     Development Status :: 3 - Alpha
     Intended Audience :: Developers