Login doesn't work after logout

[nezort11]

Describe the bug
Login doesn't work after calling AuthClient.logout because it deletes KEY_STORAGE_KEY which was set in AuthClient.create because of that there is an error when using that authClient

To Reproduce
Steps to reproduce the behavior:

1. Login
2. Refresh page (call AuthClient.create)
3. Logout (deletes Index DB)
4. Try to login (without initing using AuthClient.create)
5. It looks like it is login but after that when you start to use that client - is is broken

Expected behavior

Logout should not only delete Index DB but also set auth client to the state like after calling AuthClient.create

Fixed in the demo app: krpeacock/auth-client-demo#15