Template.load

• Added Template.load static method to load template, images and key from a folder (no localization support yet, but coming)
• Added blank templates for all possible images
• Increased test coverage

First fork rewrite

This is started as complete rewrite of assaf/node-passbook.

This modules:

• Rewritten in ES6 Classes, targetting Node 8
• Moved tests to Jest
• Added some fields values validation
• Refactored deprecated calls
• Addes ESLint + prettier code style enforcement
• Moved to @destinationstransfers scoped package (original module seems to not merging any PR in last two years)
• We use it in production at Transfers.do