[DPP-33] Added test directory to codebase
[DPP-33] Added test directory to codebase

Issue:
The build phase of the CI script was failing because the whole test
directory was not committed to the repo.

Code changes:
Added test directory.

Expected outcome:
The build phase is now expected to pass.

simone-trubian/dropp,simone-trubian/dropp,simone-trubian/dropp