tosca-parser has had some updates to bring it into partial
compliance with the TOSCA Simple Profile for YAML version 1.3.
The implementation for the following updated items has been added:
* 'attributes' was added to the keynames of the Group definition
* 'substitution_filter' was added to the keynames of the Substitution
mapping
* Added tosca.artifacts.template
* Added tosca.artifacts.template.Jinja2
* Added tosca.artifacts.template.Twig
Change-Id: Iabd748640013e0108d4ac7b4b4fb8a48c412330c