* adding new current datastore that tracks "live" records in s3 to make
  reloading current state more efficient. Takes load off mongo/elasticsearch
  datastores.
* add dynamodb support for consistency checks on s3 reads/writes
* upgrading aws-java-sdk for dynamo support
Merge pull request #45 from coryb/s3current

add S3Current datastore to track/persist live records to s3