The 'find' command was not installed in our minimal Fedora 26
and 27-based Docker images. This resulted in a non-fatal error
when performing a 'make clean'. This commit adds this utility
(available in the 'findutils' package).
Signed-off-by: Geoffroy Van Cutsem <geoffroy.vancutsem@intel.com>
Enable the Travis CI testing for all combinations of variables
that can be set at compile-time. I.e. RELEASE={0|1} and
PLATFORM={0|1}
Signed-off-by: Geoffroy Van Cutsem <geoffroy.vancutsem@intel.com>