Implement authenticate_url

[AgoraSecurity]

Solve issue #161

SUMMARY

1. Adds authenticate_url methods.
2. Bumps version number

VERIFICATION

I did some testing and it works.

Very simple code to verify:

#!/usr/bin/ruby
require 'oauth'
require 'sinatra'

CONSUMER_KEY = ENV['CONSUMER_KEY']
CONSUMER_SECRET = ENV['CONSUMER_SECRET']

raise 'Missing Consumer' if CONSUMER_KEY.nil? || CONSUMER_SECRET.nil?

set :port, 8000
set :bind, '0.0.0.0'

consumer = OAuth::Consumer.new(CONSUMER_KEY, CONSUMER_SECRET, site: 'https://api.twitter.com')

get '/' do
  "Hello World!"
end

get '/register' do
  request_token = consumer.get_request_token oauth_callback: 'https://twitter-test.agora-security.com/auth/twitter/callback'
  redirect request_token.authorize_url
end

get '/login' do
  request_token = consumer.get_request_token oauth_callback: 'https://twitter-test.agora-security.com/auth/twitter/callback'
  redirect request_token.authenticate_url
end

get '/auth/twitter/callback' do
  # Using https://developer.twitter.com/en/docs/twitter-for-websites/log-in-with-twitter/guides/implementing-sign-in-with-twitter
  # Step 1 - First request
  request_token = consumer.get_request_token oauth_callback: 'https://twitter-test.agora-security.com/auth/twitter/callback'
  # Step 2 - Receive callback
  request_token.token = params["oauth_token"]
  # Step 3 - Converting the request token to an access token
  access_token = request_token.get_access_token(:oauth_verifier => params["oauth_verifier"])
  username = access_token.params.dig 'screen_name'
  timestamp = Time.now.to_i
  params = access_token.params
  status 200
  body "Welcome #{username}. You are logged in :)"
end

Note: The code to verify, requires that you have a Twitter App, a domain and your app configured with the proper call back URL.

[AgoraSecurity]

Can't easily fix "Class has too many lines. [257/250]". I suggest that is ignored for now.

If required, I could refactor that file.

[AgoraSecurity]

@quirkey I would love your feedback when you have a chance.

[AgoraSecurity]

@pboling I would love your feedback when you have a chance.

[pboling]

This looks great to me!