[setup] Pyver>=3.6 for pip and setup.py install

Author: mpsonntag

setup.py

@@ -6,7 +6,7 @@
 
 __author__ = 'Christian Kellner, Achilleas Koutsou'
 
-if sys.version_info.major < 3 and sys.version_info.minor < 6:
+if sys.version_info.major < 3 or (sys.version_info.major > 2 and sys.version_info.minor < 6):
     sys.exit('Sorry, nixio requires python >= 3.6!')
 
 with open('README.rst') as f:
@@ -74,6 +74,7 @@ def get_wheel_data():
     license='BSD',
     packages=packages,
     scripts=[],
+    python_requires=">=3.6",
     tests_require=['pytest', 'scipy', 'pillow', 'matplotlib'],
     test_suite='pytest',
     setup_requires=['pytest-runner'],