Vendor changes

Vendoring (NEW) in github.com/Microsoft/hcsshim

vendor/github.com/Microsoft/hcsshim/version.go

@@ -0,0 +1,7 @@
+package hcsshim
+
+// IsTP4 returns whether the currently running Windows build is at least TP4.
+func IsTP4() bool {
+	// HNSCall was not present in TP4
+	return procHNSCall.Find() != nil
+}