api-identity is seeded with an Identity. GuestIdentity is used if the us...

api-identity is seeded with an Identity. GuestIdentity is used if the user is not authenticated.

Was requested by @weierophinney to create a pull-request as per: https://groups.google.com/a/zend.com/forum/#!topic/apigility-users/QOUNCLeY62s

I imagine I've done something wrong, so feel free to slap me in the right direction if anything is wrong.