Use aws-sdk-v1 instead of aws-sdk gem.

- This allows for using both v1 and v2 of the aws-sdk together.
- New AWS providers like code_deploy can now require 'aws-sdk'
Use the latest version of aws-sdk-core.
Added tests for the CodeDeploy provider.
Merge pull request #199 from wtcross/fix-aws-sdk-conflict

Use aws-sdk-v1 instead of aws-sdk gem.