feat: support service.gpus and reservations.devices (#156)

* feat: support compose.yaml `service.gpus` and `service.deploy.resources.reservations.devices` DeviceRequests to Docker container
* Fix lint error
* Adjust test comments to work with linter
* Rename DeviceRequests to DeviceReservations to be more consistent with compose nomenclature
* Device reservation changes are immutable and should trigger a container recreate rather than update

pkg/client/deploy/container.go

@@ -83,11 +83,17 @@ func EvalContainerSpecChange(current api.ServiceSpec, new api.ServiceSpec) Conta
 		}
 	}
 
+	// Device reservations are immutable, so we'll need to recreate if any have changed
+	if !reflect.DeepEqual(current.Container.Resources.DeviceReservations, newResources.DeviceReservations) {
+		return ContainerNeedsRecreate
+	}
+
 	// Check if any mutable properties changed.
 	if !current.Caddy.Equals(new.Caddy) {
 		return ContainerNeedsRecreate
 	}
 
+	// Remaining resources are mutable.
 	if !reflect.DeepEqual(current.Container.Resources, newResources) {
 		return ContainerNeedsUpdate
 	}