containerd build clean on Solaris (#203)

* containerd build clean on Solaris

Signed-off-by: Amit Krishnan <krish.amit@gmail.com>

* Vendor golang.org/x/sys

Signed-off-by: Amit Krishnan <krish.amit@gmail.com>

ctr/container_solaris.go

@@ -0,0 +1,9 @@
+package main
+
+import (
+	"errors"
+)
+
+func createStdio() (s stdio, err error) {
+	return s, errors.New("createStdio not implemented on Solaris")
+}