Use docker provider in molecule tests

[frantsao]

Prerequisites

• Put an X between the brackets on this line if you have done all of the following:
  • Checked that your issue isn't already filled: https://github.com/issues?utf8=✓&q=is%3Aissue+user%3Aidealista
  • Checked that there is not already provided the described functionality

Description

The current version of this role uses vagrant for testing. We must move to docker in order to standarize this role. And, by the way, we'll upgrade molecule version and rename role in order be Galaxy compliant.

Versions

All.