add a spec for re-saving an existing ticket

This isn't necessary for our simple in memory adapter but when I extract
this to the shared examples file for outside use it will be a nice check
for the DB backed stores that will use the id field for the PK.

Signed-off-by: Tyler Pickett <t.pickett66@gmail.com>
remove dead end implementation

Signed-off-by: Tyler Pickett <t.pickett66@gmail.com>
that's much better, none of our domain objects are leaving the core

So the adapters don't have to know about our domain object classes, just
what attributes they have. We could tighten this up and send a Struct
along but for now a hash will do.

Signed-off-by: Tyler Pickett <t.pickett66@gmail.com>
implement save_login_ticket for in_memory adapter

Signed-off-by: Tyler Pickett <t.pickett66@gmail.com>