fix: solve pylint errors

Author: ricardojdsilva87

.github/linters/.isort.cfg

@@ -1,2 +1,4 @@
 [settings]
 profile = black
+known_third_party = github3,dateutil,dotenv
+known_first_party = auth

stale_repos.py

@@ -8,10 +8,11 @@
 from os.path import dirname, join
 
 import github3
-from auth import auth_to_github
 from dateutil.parser import parse
 from dotenv import load_dotenv
 
+import auth
+
 
 def main():  # pragma: no cover
     """
@@ -42,7 +43,7 @@ def main():  # pragma: no cover
     gh_app_enterprise_only = os.getenv("GITHUB_APP_ENTERPRISE_ONLY")
 
     # Auth to GitHub.com or GHE
-    github_connection = auth_to_github(
+    github_connection = auth.auth_to_github(
         token,
         gh_app_id,
         gh_app_installation_id,