TOSCA translator is missing tests

[Thomas Spatzier]

There are currently no test cases at all defined for the TOSCA translator code, i.e. the code that translates a TOSCA template into a HOT template.

We have to add such test cases with top priority, starting from very simple ones (e.g. just one compute node) to more complex ones (e.g. with software components) where we can test if the translation matches expected output.

This will allows us (and others) first of all to better understand the code, to make sure we are always in synch with _expected_ HOT format, and to verify that refactoring we will do when working on bugs and BPs does not break anything.

[Sahdev Zala (spzala)]

Tests are created starting with BlockStorage implementation. We will continue adding more for specific use cases.