switch to go vendoring

vendor/github.com/mitchellh/copystructure/copier_time.go

@@ -0,0 +1,15 @@
+package copystructure
+
+import (
+	"reflect"
+	"time"
+)
+
+func init() {
+	Copiers[reflect.TypeOf(time.Time{})] = timeCopier
+}
+
+func timeCopier(v interface{}) (interface{}, error) {
+	// Just... copy it.
+	return v.(time.Time), nil
+}