Update to new release of moby/ipvs

hack/pin-dependency.sh github.com/moby/ipvs v1.1.0

- go to a fixed tag for `vishvananda/netns`
- no more references to `pkg/errors`

Signed-off-by: Davanum Srinivas <davanum@gmail.com>

vendor/github.com/vishvananda/netns/README.md

@@ -23,6 +23,7 @@ import (
     "fmt"
     "net"
     "runtime"
+
     "github.com/vishvananda/netns"
 )
 
@@ -48,3 +49,14 @@ func main() {
 }
 
 ```
+
+## NOTE
+
+The library can be safely used only with Go >= 1.10 due to [golang/go#20676](https://github.com/golang/go/issues/20676).
+
+After locking a goroutine to its current OS thread with `runtime.LockOSThread()`
+and changing its network namespace, any new subsequent goroutine won't be
+scheduled on that thread while it's locked. Therefore, the new goroutine
+will run in a different namespace leading to unexpected results.
+
+See [here](https://www.weave.works/blog/linux-namespaces-golang-followup) for more details.