update release to 2.1.8-dev
Merge pull request #172 from coryb/testing

s/options/choices/ for argparse
update release to 2.1.9-dev
Merge pull request #173 from coryb/testing

fix ec2_registration with hvm + s3 images
update release to 2.1.10-dev
fix cases where bool returned where CommandResult expected
verify that provision scripts in /var/local succeed before declaring Provisioning Succeeded