VOM: Additions to allow uses to UT applications that use VOM

- find object by key
- compare objects

Change-Id: I36ec8612be9482bcef7ceced2a59f7403f77b3e8
Signed-off-by: Neale Ranns <neale.ranns@cisco.com>
diff --git a/src/vpp-api/vom/acl_binding.cpp b/src/vpp-api/vom/acl_binding.cpp
index 832e232..267b02a 100644
--- a/src/vpp-api/vom/acl_binding.cpp
+++ b/src/vpp-api/vom/acl_binding.cpp
@@ -144,7 +144,7 @@
 
 std::ostream&
 operator<<(std::ostream& os,
-           const std::pair<direction_t, interface::key_type>& key)
+           const std::pair<direction_t, interface::key_t>& key)
 {
   os << "[" << key.first.to_string() << " " << key.second << "]";