Download static busybox to provide rootfs-amd64.tar.gz for test-suite.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

Remove local patch which was merged upstream.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

Add GO111MODULE=auto to GO_PKG_BUILD_VARS to allow the package to be
built in non-module mode.

Module-aware mode will be mandatory in the next golang release.

Signed-off-by: Eneas U de Queiroz <cotequeiroz@gmail.com>

Package oci-runtime-tool itself as well as oci-runtime-tests containing
runtime validation test executables as well as rootfs tarballs used by
the tests.

oci-runtime-tool can be used to generate OCI spec files or validate
OCI bundles.

To validate the OCI runtime (runc, crun, uxc, maybe others) itself,
install the 'oci-runtime-tests' package as well as 'node-npm', use
npm to install node-tap and symlink the tap executable to /usr/bin.
Then
cd /usr/libexec/oci-runtime-tests
tap *.t

Signed-off-by: Daniel Golle <daniel@makrotopia.org>