Update setup.py

Author: revolunet

setup.py

@@ -1,13 +1,12 @@
 #!/usr/bin/env python
 from distutils.core import setup
 
-with open("README.md", "r", encoding="utf-8") as fh:
+with open("README.rst", "r", encoding="utf-8") as fh:
     long_description = fh.read()
 
 setup(
     name='pypdftk',
     description='''Python wrapper for PDFTK''',
-    long_description_content_type="text/markdown",
     long_description=long_description,
     version='0.5',
     author='Julien Bouquillon',