Netplugin changes to match model change (epg is no longer a child of nw). (contiv#380)

* Netplugin changes corresponding to contiv-experimental/contivmodel#23

* Changes from merge

* Review comments

Author: jojimt

netmaster/objApi/objapi_test.go

@@ -1089,6 +1089,13 @@ func TestEpgPolicies(t *testing.T) {
 	checkCreateNetwork(t, false, "default", "newnet", "data", "vxlan", "20.1.1.1/16", "20.1.1.254", 2, "", "")
 	checkCreateEpg(t, true, "default", "newnet", "group1", []string{}, []string{})
 
+	// verify name clash between network and epg is rejected
+	checkCreateEpg(t, true, "default", "contiv", "contiv", []string{})
+	checkCreateNetwork(t, true, "default", "group1", "data", "vxlan", "20.1.1.1/16", "20.1.1.254", 1)
+	// verify network association cant be changed on epg
+	checkCreateNetwork(t, false, "default", "newnet", "data", "vxlan", "20.1.1.1/16", "20.1.1.254", 2)
+	checkCreateEpg(t, true, "default", "newnet", "group1", []string{})
+
 	// change policy and verify EPG policy changes
 	checkCreateEpg(t, false, "default", "contiv", "group3", []string{"policy1"}, []string{})
 	checkCreateEpg(t, false, "default", "contiv", "group3", []string{"policy2"}, []string{})