Merge pull request #9 from talko/fixes/retry

Retry on errors as specified in DynamoDB doc
This is just a bit more accurate.. 
Merge pull request #10 from DeadZen/patch-1

This is just a bit more accurate.. 
Merge pull request #12 from talko/master

Add scan support
Merge branch 'master' of https://github.com/wagerlabs/ddb