accepting proc for options

[LeFnord]

this solves #429

host and base_path accepts String, proc or lambda

[dblock]

Make it into a full sentence, like "The host and base_path options also accept ..".

[Lordnibbler]

In addition to that, I think providing some trivial usage example would be super helpful in the docs here:

add_swagger_documentation(
  base_path: proc { |foo| foo.host =~ /^example/ ? '/api-example' : '/api' }
)

[dblock]

I am going to merge this, my comments are more like next steps. We can still change things wrt my arity comment, but I'd be ok with shipping it as is too.

[LeFnord]

yeap … good point
to your last comment, also yeap, agreeing, but also thinking issues are not enough for that,
better something like tickets, card, whatever, what is better suitable for developing ideas

[Lordnibbler]

Sure, thanks for addressing this; I left a small comment suggesting we have a usage example for the base_path option using a proc in the docs so folks dont necessarily have to dig in the tests/source

[dblock]

@Lordnibbler do PR that!

[Lordnibbler]

Sure

[Lordnibbler]

#442