Correct links in document, prepare code for a new structure of the card.js's iframe

[guzzilar]

PR Purpose

• Correct links in the README.md file.
• Enhance the code, prepare it for a new structure of the card.js's iframe

  The effect after you merge this PR.

It will be possible to move all of card.js files inside card.omise.co to cdn.omise.co/...

The deployment instruction

The steps to deploy are as follows:

• Deploy /build/javascripts/card.js to https://cdn.omise.co/
• Deploy everything inside /build folder to https://cdn.omise.co/card-2.0
  (you could remove https://cdn.omise.co/card-2.0/javascripts/card.js because we will keep it outside of this folder (see above)).

Noted:

• if you want to change the name of the iframe's folder (https://cdn.omise.co/card-2.0) you could change it in source/javascripts/card-2.0.0.js.coffee
  Line 10: @directory = "/card-2.0"
• You have to re-build again after merge this PR.

[guzzilar]

Oops, wait it failed in CircleCI

[guzzilar]

Ok, fine. let's continue review :smile:

[fred]

Great!

[guzzilar]

FYI: for the committed 0372d27 At the begin, I created a new file source/javascripts/card-2.0.0.js.coffee for dev card.js version 2 and leave the old one in source/javascripts/card.js.erb.

So, when the committed 0372d27 comes, I decided to remove source/javascripts/card-2.0.0.js.coffee and moved code into source/javascripts/card.js.erb. Also, changed the file extension from card.js.erb to card.js.coffee.

So, when you look in the Git file changed. It will show as

• renamed source/javascripts/card-2.0.0.js.coffee to source/javascripts/card.js.coffee
• removed source/javascripts/card.js.erb