Added a back off and try again catch try - catch block to wait for stabilisation.

It backs off for the standard sleep period which is 30 seconds and will return until the deploy times out...

http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/query-api-troubleshooting.html
Log the error message we are consuming
Merge pull request #148 from guardian/back-off-buddy

Added a back off and try again catch try - catch block to wait for stabilisation.