Add CrossZoneLoadBalancing to ELBs
Add CrossZoneLoadBalancing to ELBs

This will ensure that traffic is balanced across backend containers
evenly.

http://docs.aws.amazon.com/ElasticLoadBalancing/latest/DeveloperGuide/how-elb-works.html#request-routing

Fixes #640

vfulco/empire,remind101/empire,iserko/empire,iserko/empire,remind101/empire,zofuthan/empire,mhahn/empire,mhahn/empire,vfulco/empire,mhahn/empire,remind101/empire,iserko/empire,zofuthan/empire