Update setup.py

Author: makism

setup.py

@@ -33,6 +33,7 @@
       keywords='eeg fMRI meg connectivity graphs neuroimage brain',
       url = 'https://github.com/makism/dyfunconn',
       download_url = 'https://github.com/makism/dyfunconn/archive/v1.0.0-beta.1.tar.gz',
+      python_requires='~=3.6',
       packages=packages,
       install_requires=['numpy', 'scipy', 'networkx', 'matplotlib', 'statsmodels', 'scikit-learn', 'bctpy'],
       package_dir={'dyfunconn': 'dyfunconn'},