Merge pull request #1 from stephenh/master

Create a .aws_credentials.json for the elastic-mapreduce client.
AWS_SECREY_KEY as alias for AWS_SECRET_ACCESS_KEY

aws-java-sdk uses a different env name for their secret key in the default credential provider (https://github.com/aws/aws-sdk-java/issues/50)
Merge pull request #2 from ogrodnek/master

AWS_SECRET_KEY alias for AWS_SECRET_ACCESS_KEY
Update README for .aws-tools directory.
Import emr 20130708.
Force ruby1.8 for elastic-mapreduce-ruby.