method and tests to add an instance to an environment
find an environment by its name off the api object
find instance by its AWSM id
Environment#remove_instance with a given instance object removes an instance via API
Environment.by_name using resolver

Resolver is way way faster and more accurate.
Minor refactoring, also remove usage of 1.9 hashes

We still have to be sensitive to customers using old rubies.
Test instance removal more, and respond with json in specs so they load the response correctly