Set minimum version of python to 3.5

Author: peymanslh

setup.py

@@ -66,7 +66,7 @@
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
     ],
-    python_requires='>=3.4',
+    python_requires='>=3.5',
     tests_require=['pytest'],
     install_requires=install,
     extras_require={