implement ticket granting ticket storage for in memory adapter

Signed-off-by: Tyler Pickett <t.pickett66@gmail.com>
refactor existing ticket saving into an easier to extend pattern

Signed-off-by: Tyler Pickett <t.pickett66@gmail.com>
rework bulk retrievers the same way as savers

Signed-off-by: Tyler Pickett <t.pickett66@gmail.com>
implement a simple == method on tickets

Signed-off-by: Tyler Pickett <t.pickett66@gmail.com>
use safer public_send for that dispatch

Signed-off-by: Tyler Pickett <t.pickett66@gmail.com>
rework fields method to reduce the stack depth and nil checks

Signed-off-by: Tyler Pickett <t.pickett66@gmail.com>
add NilTicket that quacks like a ticket but doesn't really do anything

Signed-off-by: Tyler Pickett <t.pickett66@gmail.com>
implement login ticket retrieving on the core side of Persistence

Signed-off-by: Tyler Pickett <t.pickett66@gmail.com>
implement TGT loading on the core side of Persistence

Signed-off-by: Tyler Pickett <t.pickett66@gmail.com>
refactor ticket loading methods on Persistence

We'll easily be able to expand this to load all other tickets by their
ticket string by simply adding their underscored names.

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