DOC: specify long_description_content_type as RST in setup.py

Author: qwhelan

setup.py

@@ -168,6 +168,7 @@ def get_long_description():
     maintainer_email="[email protected]",
     description="Fast NumPy array functions written in C",
     long_description=get_long_description(),
+    long_description_content_type="type/x-rst",
     url="https://github.com/pydata/bottleneck",
     download_url="http://pypi.python.org/pypi/Bottleneck",
     license="Simplified BSD",