Jitterbug should maintain it's own local::lib for Perl modules

[leto]

Currently projects being tested in a Jitterbug instance can't depend on each other, unless they are installed somewhere that the Jitterbug process can find them, either system-wide or in a manually configured local::lib instance. Even then, if the newest commit x of project a requires the newest commit y of project b, unless commit y of project b is installed outside of Jitterbug, tests will fail, which sucks.

This will make Jitterbug's testing environment containable and much easier to debug, rollback, etc.

This commit from Ambikon::IntegrationServer will probably be useful:

https://github.com/solgenomics/Ambikon-IntegrationServer/commit/22a173100c76bfd487768eec9baa7f5461b522d6

[leto]

Carton is looking pretty awesome: https://github.com/miyagawa/carton