------------------
- New endpoint for uploads to storage,
:class:`craft_store.StoreClient` and
:class:`craft_store.UbuntuOneStoreClient` require a
new initialization new parameter
- Setting credentials while credentials are already set is no longer allowed
:class:`craft_store.errors.CredentialsAlreadyAvailable` is raised if
credentials already exist
- NotLoggedIn exception renamed to
:class:`craft_store.errors.CredentialsUnavailable`
- Early checks are now in place for keyring availability before a login attempt
takes place