had to update the POM to use the latest snapshots
incorporated get internetGatewayById alongside getInternetGatewayId in existing tests

- leveraged existing tests to incorporate getInternetGatewayById, this
was new functionality that needed testing but did not necesscarily
require new tests to achieve the end result.
- added some thread sleeps throughout touched files, tests continually
failed for me due to latency/race-condition issues with cloud provider
(aws)
Ref #3