Fix bug where config dir isn't created if it doesn't exist.

gmailfilter/_command.py

@@ -23,6 +23,7 @@ def run():
     else:
         run_new_filter()
 
+
 def run_old_filter():
     """Run the old, pre v1 filter agent. This will get deleted soon."""
     rules_path = get_filter_file_or_raise()

gmailfilter/_connection.py

@@ -360,6 +360,9 @@ def read_config_file(cls, path=None):
     def write_template_config_file(cls, path=None):
         """Write a template config file to disk."""
         path = path or default_credentials_file_location()
+        directory = os.path.dirname(path)
+        if not os.path.exists(directory):
+            os.makedirs(directory)
         with open(path, 'w') as template_file:
             template_file.write(textwrap.dedent('''
                 # Credentials config file.

setup.py

@@ -1,5 +1,8 @@
 #!/usr/bin/env python3
 
+import sys
+
+assert sys.version >= '3'
 from setuptools.command.test import test as TestCommand
 from setuptools import find_packages, setup