The masakari.test module is used only by unit tests. Move it to
the test code directory so that users can more easily determine
that the file is used only in testing.
Also make sure that the test codes are omitted in coverage report,
because we do not care coverage of test code.
Change-Id: I2ffc75bd2efacf4a18f546700af05abb7368fdd3
d75d216589