Makefile: fix default unit tests
Makefile: fix default unit tests

- An earlier change meant 'make test-unit' by itself was running no
  unit tests, unless GO_TEST_RUN was set.

opentable/sous,opentable/sous,opentable/sous,opentable/sous,opentable/sous,samsalisbury/sous,samsalisbury/sous,samsalisbury/sous,samsalisbury/sous,samsalisbury/sous