* Added Email of Keystone to Identity
After the successful login to keystone, the Email of the logged in user
is fetch from keystone and provided to `identity.Email`.
This is useful for upstream software that uses the Email as the primary
identification.
* Removed unnecessary code from getUsers
* Changed creation of userResponse in keystone
* Fixing linter error
Co-authored-by: Christoph Glaubitz <christoph.glaubitz@innovo-cloud.de>