Allow email to be configured per environment

[ikottman]

Alerts and reports right now share the same email in all environments. It would be useful to be able to flex what email to send to per environment.

Example pickaxe.yml for a backwards compatible approach:

namespace:
  app: app_name_here
environments:
  dev: https://devurl.com
  production: https://produrl.com
environment_emails:
  dev: 
    - dev_support@foo.com
  production: 
    - production_support@foo.com

Either emails or environment_emails can be specified. Not both.

cleaner, but not backwards compatible approach:

namespace:
  app: app_name_here
environments:
  dev: 
    url: https://devurl.com
    email: dev_support@foo.com
  production:
    url: https://produrl.com
    email: production_support@foo.com

Using a hash also allows for additional configuration per environment in the future.

[bbaugher]

I like what you have for your new config. I think we could support the old configuration and your new suggested approach by inspecting the value for each environment. We could deprecated the old approach and eventually remove it.

[bbaugher]

This was completed by #7

[bbaugher]

This was released in 2.3.0