Refactored and tested waiting for env status change
2-spaces and 1.9 hash syntax for environment.rb
Wait for up to 2 minutes for new env to be healthy.

Beanstalk's default healthcheck runs every 30 seconds and requires 3 successive greens to be flagged as healthy.
We've been seeing cases where the environment comes up in a Red state (does the healthcheck start running too soon?) and flicking over to green shortly after deployment.

This change makes Beanstalkify treat these cases as successes.
Merge pull request #7 from rickgrundy/wait_for_green

Wait for up to 2 minutes for new env to turn healthy