Fix usage of inherited Sinatra::Base classes keyword arguments

[duduribeiro]

Closes #1669
Using keyword arguments on inherited classes from Sinatra::Base breaks
with ArgumentError: wrong number of arguments (given X, expected 0) on Ruby 3

This can be reproduced by this minimal example:

app.rb

require 'sinatra'

class KWApp < Sinatra::Base
  def initialize(app:, comp:)
    p app
    p comp

    app.get '/' do
      "Hello from KWApp"
    end

    super(app)
  end
end

class PApp < Sinatra::Base
  def initialize(app, comp)
    p app
    p comp

    app.get '/' do
      "Hello from PApp"
    end

    super(app)
  end
end

config.ru

require "./app"
require "sinatra"

map "/" do
    run KWApp.new(app: Sinatra.new, comp: 2)
end

map "/p" do
    run PApp.new(Sinatra.new, 2)
end

This example works on ruby < 3 but it breaks when using Ruby 3 with:

 KWApp.new(app: 1, comp: 2)
ArgumentError: wrong number of arguments (given 1, expected 0; required keywords: app, comp)
from (pry):3:in `initialize

This commit fixes the usage of it on Ruby3 by allowing the method to
accept both positional and keyword arguments.

[dentarg]

@duduribeiro Nice! Do you think you could add your example as a test?

[duduribeiro]

@dentarg yeah!. Will do it and ping you after.

Thanks 🍻

[duduribeiro]

hey @dentarg,
I've added a test of it. Can u check if it is ok?

Thanks

[duduribeiro]

On trusty rvm is failing to install ruby 3.0.0-preview1, but upgrading to xenial makes the jruby build fails.

[dentarg]

I think we should try to get the test suite running on GitHub Actions

[duduribeiro]

@dentarg wanna merge this and work on GH actions after? I can work on this in a new PR if I get access on it.

Also, this will be importante because:
https://blog.travis-ci.com/2020-11-02-travis-ci-new-billing

Building on a public repositories only
We love our OSS teams who choose to build and test using TravisCI and we fully want to support that community. However, in recent months we have encountered significant abuse of the intention of this offering (increased activity of cryptocurrency miners, TOR nodes operators etc.). Abusers have been tying up our build queues and causing performance reductions for everyone. In order to bring the rules back to fair playing grounds, we are implementing some changes for our public build repositories.
For those of you who have been building on public repositories (on travis-ci.com, with no paid subscription), we will upgrade you to our trial (free) plan with a 10K credit allotment (which allows around 1000 minutes in a Linux environment).

[dentarg]

@duduribeiro I'm not maintainer or collaborator, just a fellow contributor :-) It is @namusyaka or @jkowens that can merge PRs

[dentarg]

I think Actions should work in your fork of Sinatra, so you can work on it right now if you want

[jkowens]

Switching to Github Actions would be 💯

[jkowens]

I've worked out the Travis issues. Should be good if you rebase master. Thanks!

[duduribeiro]

@jkowens thanks!

This PR is ready for review now 🍻

[jkowens]

This looks good to me! @namusyaka can you take a look as well?

[namusyaka]

Looks good, thanks.