Add test for git strategy

to check uniform interface
get complete working copy for git api strategy
remove param from update

Assumes right directory context now
rename Bimble#update to Bimble#bundle_update
update returns PR URL
bundle needs to update.

oops
Print PR details after run
separate commit and open
remove debug print
detect whether lockfile has changed
Swap to using github api strategy in default script

So we can handle large repositories
Add github api update method
DRY up update method