* Fix TS stuff
* single quote + trailing commas for tests folder
* Specific for includes... allow for ts testing later
* Export Invoice and Rate interfaces to library user
* Use prepare
* test checks format and lint
* Keymanagment: new Buffer() is deprecated, use new Buffer.from() instead
Also, you only generate your initial keypair once, so every time you use the key in your app, it is not derived, from the previously keypair var, but e.g. from environment variables
* Docs: Make easier to understand, use ES6 Javascript
* added invoices api
* added semicolon and replaced lets to const
* updated only slightly for still using javascript but linted with eslint
* reworked code to typescript with async await support
* going on with ts refactoring
* going on with ts refactoring
* going on with ts refactoring
* adde sample code
* fix for typescript
* using request-promise again
* Fix: removed not needed interface
