Add a 'test' that lists the available EC2 instance types.

When AWS adds new instance types, the AWS SDK is updated to include them, and this
plugin is updated to bring in the new version of the SDK. In order to confirm that
doing so actually does make the new instance types available, this 'test' lists
the known instance types while the plugin is being tested.
Correct copyright notice
Merge pull request #41 from kpfleming/list-instance-types-during-build

Add a 'test' that lists the available EC2 instance types.