Changes based on our discussions in #285 and #286 the identity map is now a global on the Twitter module and can be disabled or replaced. I've also switched back to fetch_or_new, I left an alias to fetch_or_create in Twitter::Base though it may not be necessary if the changes from my previous PR have not been released.
added global identity map
switch back to fetch_or_new
Updated Twitter::Base and Twitter::Identity to use global identity map.
The identity map is now exposed as a global and can be disabled:
Twitter.identity_map = false
Likewise, it can be replaced by a custom implementation:
Twitter.identity_map = My::Custom::SqliteIdentityMap
This alias can be removed.
Remove alias, no longer necessary for backwards compatability