We want be able to build kernels for different archs without that they
clash with each other so we but the generated files into an $arch subdir.
Signed-off-by: Natanael Copa <natanael.copa@docker.com>
Beginning of a proper test suite, using qemu. Test just runs docker
for now, will add further integration tests.
Signed-off-by: Justin Cormack <justin.cormack@docker.com>