setup.py: Require setuptools 36.2.7

If the wheel is generated with older setuptools it will have incorrect
requirements for Python 3, since some of the requirements use
environment markers and there was a problem with those in older versions
of the setuptools.

See pypa/setuptools#1081 and
pypa/setuptools#1108 for details.

setup.py

@@ -2,5 +2,5 @@
 
 if __name__ == '__main__':
     setuptools.setup(
-        setup_requires=['setuptools>=34.0', 'setuptools-gitver'],
+        setup_requires=['setuptools>=36.2.7', 'setuptools-gitver'],
         gitver=True)