Generic test class

Description

Testing needs to be configured for each and every connector there is. A generic approach to the testing class would reduce configuration time and required knowledge to build connectors.

Explanation

Using the generic (but deprecated) validation-method ('validator.validateThing') would allow the test-class to be applicable to all thing-types, which the connectors are for.

Dependencies, issues to be resolved beforehand

Needs to be merged: core-tools!6 (merged)

A new tag of openstapps-core-tools containing the MR-content needs to be created. (e.g. 0.2.1)