fix long description for pypi

Author: dobe

setup.py

@@ -22,6 +22,7 @@ def get_version():
     version=get_version(),
     description='Pytest testing utilities with docker containers.',
     long_description=readme,
+    long_description_content_type="text/markdown",
     classifiers=[
         "Programming Language :: Python :: 3",
         "Programming Language :: Python :: 2.7",