Allow a user to configure EM via app manifest as opposed to a user-provided service instance

[swilliams11]

Consider using the env: block in the app manifest to configure Edge Microgateway.
https://docs.cloudfoundry.org/devguide/deploy-apps/manifest.html#env-block

This is an alternative configuration to use the user provided service instance (cuups). The current implementation of the decorator supports EM config for all EM instances in a CF org and space. If multiple developers are using the same org and space and they want to have separate configurations for EM then this is not current supported.

This new feature would allow a developer to include EM config via the env variable in the application manifest and the decorator should use that configuration to start the EM instances for that app.

[swilliams11]

I think this is going to require a significant amount of rework on the existing EM decorator. The reason is that the EM configure command currently executes in the CF staging container. When the staging container starts it looks for the "edgemicro" user defined service to determine how to configure EM on start up. This means that all of this code must be moved to the .bash_profile script instead. The configure step has to execute within the droplet, instead of the CF staging container.