Log Message:
Update ruby-celluloid-pool to 0.20.5.

0.20.5 (2015-09-30)
-----
* Resumed updating changelog. Not much as changed -- mostly keeping version sync \ 
with other gems.
* Revamped test suite, using shared RSpec configuration layer provided by \ 
Celluloid itself.
* Updated gem dependencies provided by Celluloid::Sync... extraneous gems \ 
removed, or marked as development dependencies.