Correct span in disambiguate_location for Oxfordshire

Related to #508
Specify town in Oxfordshire disambiguate_location

Part of #508

This seems like a bit of a misuse of this feature, mostly because I'm
specifying a county in a parameter called town, but it appears to fix
the immediate problem of not being able to find streets in oxfordshire.
Convert carton.lock to cpanfile.snapshot

Carton 1.0 changed the file format of the module list
Fixes #511
we need local::lib which wasn't previously included
Merge remote-tracking branch 'upstream/master'