Add real tests

The only test consist in displaying that it passes:
```
add_test(NAME testpass COMMAND ${CMAKE_COMMAND} -E echo "pass")
```
See https://github.com/jamesfishbaugh/shape4D/blob/master/testing/CMakeLists.txt

I suggest to add few tests exercising the functionality of the module.

cc: @jamesfishbaugh @bpaniagua