Update to virtualenv 1.10.1
Add new LB nodes before removing old; fixes error caused by HPCS' rule that a LB must have at least one node
Make load balancers region-specific (individual implementors can ignore this if they wish)
Merge pull request #6 from SJMc/master

Update to virtualenv 1.10.1 (from pypi); fix hpcs load balancer node creation