snapshot support

Makes it possible to get events after a specific aggregate_version by using the parameter after_aggregate_version in find

big bang release dep. on sandthorn 1.0.0

This release is in dep on the main gem sandthorn 1.0.0

the interface between the driver and the main sandthorn gem is now much cleaner.

Migrate connection

Before this version migration could only be made on url string, its now possible to migrate on a connection as well.

SandthornDriverSequel.migrate_connection

Serialization moved to driver

The serialization mechanism are now moved to the driver. This driver only works with Sandthorn version 0.11.0 and above.