Merge pull request #503 in VECTO/vecto-sim from ~EMQUARIMA/vecto-sim:develop to develop

* commit '9515a65f':
  removing MS Unit Test Framework
  switch to NUnit testframework
  remove legacytest project (Vecto 2.2)
  making testcase work with nunit 3.7
  change working directory for nunit tests
  convert all tests to nunit
  removing duplicate file
  adapting testcases to run under NUnit 3.7
  switch to NUnit 3.7