Allow environment variables to be injected into configuration file variables

[KamBha]

Currently, you cannot load environment variables into a config file. This forces you to setup different configurations even if the configuration only needs minor modifications (eg server names)

It would be nice if we could specify environment variables into the config file.

It looks like drop wizard supports this idea:-

https://www.dropwizard.io/0.8.0/docs/manual/core.html#environment-variables

[stickfigure]

That would be cool. But there is also another way - GWizard uses the Dropwizard configuration library under the covers, so it allows the same mechanisms for setting properties. You can pass in values as java propeties:

https://github.com/gwizard/gwizard/tree/master/gwizard-config