SNS and SQS screen improvements
navigation from SNS to SQS endpoints in same account
update SQS policy when it is subscribed to SNS topic
Allow editing MessageRetentionPeriod.
Use enum rather than Strings for queue attribute names.
changed service test names
so that afterPropertiesSet is not called
Update README.md

to kick off new build
changes based on code review feedback
Merge branch 'snsImprovements' of github.com:claymccoy/asgard into snsImprovements
Merge pull request #414 from claymccoy/snsImprovements

Sns improvements