abbey.py - python script for creating AMIs in the VPC environment

abbey.py will launch an instance into a VPC, run ansible on it
and monitor it for updates using an SQS queue.  At the end of
the ansible run it will create an AMI and terminate the instance.

Example:
```
python -u abbey.py -p edxapp -t m1.medium   -d edx -e stage -i /home/jarv/.ssh/edx-secure-identity --configuration-version jarv/abbey-ami -b ami-b71d33de --vars /var/tmp/extra-vars.yml
```

Where /var/tmp/extra-vars.yml has overrides for repo versions such as:
```
---
edx_platform_commit: jarv/test
```