Multiple values for same docker run argument

[jacoscaz]

The --add-host argument to docker run can be repeated multiple times to add more hosts:

docker run --add-host one:X.X.X.X --add-host two:Y.Y.Y.Y ...

Support for custom docker run arguments was added in #95 but the optionize function at https://github.com/mrsked/mrsk/blob/4e9c39f26df6b0b6da9deb2517c51252d4b7df03/lib/mrsk/utils.rb#L30 doesn't appear to support array-like values.

Is this something you would like to support? Would you accept a PR? It's my very first time reading and writing Ruby but this seems easy enough.

[jacoscaz]

Nevermind, I'm an idiot. Of course I have found the solution only after posting this. Looked into the code some more and this is possible:

    options:
      "add-host": 
        - one:X.X.X.X
        - two:Y.Y.Y.Y