Initial retry implementation for s3 (untested)
add error retry tests
add test for httpc error
s3: put_object test and dialyzer fixes
s3: add default_retry that takes number of retries
Merge pull request #109 from talko/s3_retry

S3 retry
Merge pull request #112 from smilerlee/master

Updated to the newest DynamoDB API
Update erlcloud_ec2.erl

Support multiple security groups when no network specs defined.
Merge pull request #114 from jvanvleet/master

Support multiple security groups when no network specs defined.
Minor fixes
Updated GSI KeySchema to support both hash key and hash-and-range key