split.sh

My attempt at automate @fabpot monorepo to multirepo stragegy
according to what he describe in his keynote symfony live paris
2016

All advanced features @fabpot talked about
  * performance issues
  * volume on hard drive
  * tagging

Are not implemented yet. It is just a way to have a feel for it

Some stuff TO DO
  * propagate tags to mulitrepo
  * build a smart merge commit message
  * setup config in a rc file
  * nicer logs and error reporting
  * build better checks for each steps to avoid bad pushes

Advanced tasks would be
  * maintaining multiple branches

Quotes from @fabpot
@see http://paris2016.live.symfony.com/speakers#session-1728
  Google and Facebook store their codebase into one giant code repository.
  Symfony has been doing the same thanks to Git and some secret sauce with great
  success since 2010.

  Having only one repository makes code management much easier for end users and
  core contributors: one central place to submit pull requests and report bugs,
  simple cross-project atomic changes, fast releases, and more.

  But what about users wanting to use only one component? Enter "repository
  splitting". After learning some theory about subtree splits and how to create
  them with the Git built-in but slow "subtree" command, I will talk about the
  tool I developed using libgit2 and Go to make the process almost real time.

  If you have a microservice oriented architecture and manage one repository per
  microservice, you could probably benefit from using the same technique with
  one repository for development and read-only splits for packaging and
  deployment.