REVERT ME: Linking to Patrick's ec2 repo for now
Adding extra instance types
Adding mapreduce module
Adding automatic resolve of AMI
Resolve AMI region automatically
Changing spark version and availability zone fix
Slight change to AMI versioning
Removing unnecessary parsing
Adding support for  tag
Some changes in response to Josh
Decoupling spark version from ami
Adding spark shark modules
Fixing syntax error
Removing now defunct ami documentation
Minor doc cleanup
Remving support for old scripts
Re-working spark versions to use templates
Support for multiple hadoop versions
Cleanup of AMI tag
Add support for Spark on Yarn on a secure Hadoop cluster