- Add unit test for when case when the cookie doesn't match the db.

- Move code into User.signout method to further encapsulate the code.

app/main/views/sign_out.py

@@ -1,5 +1,5 @@
-from flask import redirect, session, url_for
-from flask_login import current_user, logout_user
+from flask import redirect, url_for
+from flask_login import current_user
 
 from app.main import main
 
@@ -7,6 +7,4 @@ from app.main import main
 @main.route('/sign-out', methods=(['GET']))
 def sign_out():
     current_user.sign_out()
-    session.clear()
-    logout_user()
     return redirect(url_for('main.index'))