feat: add restriction for python 3

Add a restriction for python 3 so that installing this software with python 2 isn't possible.

Should fix GH-10.

gitea_auto_update/update.py

@@ -7,6 +7,7 @@ All rights reserved.
 License: GNU General Public License
 '''
 import os
+import sys
 import logging
 import configparser
 import fire
@@ -74,8 +75,12 @@ def updater(settings='settings.ini'):
                   config.get('Gitea', 'tmpDir'),
                   config.get('Gitea', 'system'))
 
+
 def main():
+    if not sys.version_info[0] == 3:
+        sys.exit("Sorry, Python 2 is not supported. Please update to Python 3.")
     fire.Fire(updater)
 
+
 if __name__ == '__main__':
   main()

setup.py

@@ -4,7 +4,7 @@ with open("README.md", "r") as fh:
     long_description = fh.read()
 
 setuptools.setup(name='gitea_auto_update',
-      version='2.0.5',
+      version='2.0.6',
       description='A script which can update gitea to a new version.',
       long_description=long_description,
       long_description_content_type="text/markdown",
@@ -18,6 +18,7 @@ setuptools.setup(name='gitea_auto_update',
             "Operating System :: Unix",
       ],
       keywords=['gitea', 'update', 'debian', 'linux'],
+      python_requires='>=3',
       install_requires=[
             'requests',
             'packaging',