VOL-381 add unum container to support ONOS cluster formation under swarm

Change-Id: Ic260edda19bb199ed040f05164ab605f28c919d0
diff --git a/unum/vendor/github.com/kelseyhightower/envconfig/env_os.go b/unum/vendor/github.com/kelseyhightower/envconfig/env_os.go
new file mode 100644
index 0000000..a6a014a
--- /dev/null
+++ b/unum/vendor/github.com/kelseyhightower/envconfig/env_os.go
@@ -0,0 +1,7 @@
+// +build appengine
+
+package envconfig
+
+import "os"
+
+var lookupEnv = os.LookupEnv