avoid ulimit -n exception with >100 Celluloid::Actors running

see relevant gist for more details:

https://gist.github.com/Felixyz/5788285
avoid ulimit -n exception with >100 Celluloid::Actors running

see relevant gist for more details:

https://gist.github.com/Felixyz/5788285
Merge branch 'ulimit_exception'

* ulimit_exception:
  avoid ulimit -n exception with >100 Celluloid::Actors running
  Add a Bitdeli badge to README