Remove code-of-conduct.md and version.md when clean
Remove code-of-conduct.md and version.md when clean

So we can use latest files after make clean.

Signed-off-by: Qiang Huang <488e06933c295c76472a67dbc6657ac40a756953@huawei.com>

wking/opencontainer-specs,opencontainers/specs,cloudfoundry-incubator/specs,hqhq/runtime-spec,hqhq/specs,ujuc/specs,opencontainers/runtime-spec,laijs/specs,wking/opencontainer-runtime-spec,vbatts/specs,jonboulle/specs