These tests should be reporting on the structure and correctness of mixer
and its user interface. Due to them running very slowly on the Travis CI
environment, they are not run by default, but can be run locally with
make batcheck.
This patch also introduces a docker container to do the build, so we do not
have to worry about running this in different environments such as Travis
CI. The tests are thus confined to a strict, well-known workspace,
and we can avoid many dependency problems.
Signed-off-by: Tudor Marcu <tudor.marcu@intel.com>