Support type array for overriding environments variables

[tduyng]

For now we only support number and boolean types for overriding environments variables.

It will be helpful if we could support also the array type. Thanks!

[Crow-EH]

+1.

We could parse env variables into arrays when type: array, and require comma separated values.

e.g.

env_mapping.yaml :

MY_ARRAY:
  key: myArray
  type: array

and env var :

MY_ARRAY="foo,bar,fizz,buzz"

would be equivalent to this in the yaml config :

myArray:
  - foo
  - bar
  - fizz
  - buzz