Add Compat API for Update

The Docker endpoint here is kind of a nightmare - accepts a full
Resources block, including a large number of scary things like
devices. But it only documents (and seems to use) a small subset
of those. This implements support for that subset. We can always
extend things to implement more later if we have a need.

Signed-off-by: Matt Heon <mheon@redhat.com>

test/apiv2/20-containers.at

@@ -730,6 +730,12 @@ if root; then
   eid=$(jq -r '.Id' <<<"$output")
   t POST exec/$eid/start 200 $cpu_weight_expect
 
+  # Now use the compat API
+  echo '{ "Memory": 536870912 }' >${TMPD}/compatupdate.json
+  t POST containers/updateCtr/update ${TMPD}/compatupdate.json 200
+  t GET libpod/containers/updateCtr/json 200 \
+    .HostConfig.Memory=536870912
+
   podman rm -f updateCtr
 fi