style: format code with Black and isort

This commit fixes the style issues introduced in b3d7ada according to the output
from Black and isort.

Details: #31

app.py

@@ -9,8 +9,8 @@
 from githubapp import webhook_handler
 from githubapp.events import (
     CheckSuiteRequestedEvent,
-    IssueOpenedEvent,
     IssueEditedEvent,
+    IssueOpenedEvent,
 )
 
 from src.managers.issue import handle_tasklist

tests/managers/test_issue.py

@@ -1,9 +1,9 @@
+from unittest.mock import Mock, patch
+
 import pytest
 
 from src.managers.issue import handle_tasklist
 
-from unittest.mock import patch, Mock
-
 
 @pytest.fixture(autouse=True)
 def get_repository(repo_batata):

tests/test_app.py

@@ -4,7 +4,7 @@
 import markdown
 import pytest
 
-from app import app, handle_check_suite_requested, sentry_init, handle_issue
+from app import app, handle_check_suite_requested, handle_issue, sentry_init
 
 
 def test_sentry_init(monkeypatch):