Support multiple option calls to create an array

[fulldecent]

Example:

program --ignore bob --ignore mary

Will create configuration of:

ignore: ['bob', 'mary']

Reference: gjtorikian/html-proofer#377

[fulldecent]

Ping @pedrozath @DirtyF Can you please review if this suggestion is in scope for the project?

[parkr]

I don’t have time to address this, but I would be happy to see if OptionParser supports this. AFAIK, many command line utilities support this behaviour so it wouldn’t be out of line to support.