wait / check for environment creation

[nergdron]

When creating a bunch of environments, it can take a really long time. It'd be great if instead of each call to elasticbeanstalk_env blocking while it creates a single environment, if elasticbeanstalk_env had a wait: option like some other resources, that could be set to "no", so that all environment creates could be started at once. Then there'd need to be another task like "elasticbeanstalk_env_wait" which would block waiting for the creation to complete, and return the operation results.

This way, you could have a list of app/environment names, start them all at once, then wait for them all to finish, thus saving tons of time on large EB deployments.