RAMPT - v4.0 (#9)

* Full demo example

* POC v4.0.0

* Update README.md

* fix npm publish

* v4.0.0-alpha.1

* fix minor bug for custom Tag creation.

* enhance Title element.

* update examples.

* fix validation errors for AMP example

* add coverage badge

* v4.0.0

* fix travis

Bump 3.0.0-rc0

Bump 2.3.0

publish: Update package to release 2.2.1

generated from commit 081d650

publish: Bump package to 2.2.0. 

generated from commit 65f3f82