face: Implementing Face::getUri() method

Change-Id: I9a9f774b95784e5b7ec75472f1cc6cf64c4e5d7b
Refs: #1319
diff --git a/tests/face/unix-stream.cpp b/tests/face/unix-stream.cpp
index 921c1ff..09ee905 100644
--- a/tests/face/unix-stream.cpp
+++ b/tests/face/unix-stream.cpp
@@ -148,6 +148,11 @@
 
   BOOST_REQUIRE(static_cast<bool>(m_face1));
 
+  std::string face1uri = m_face1->getUri().toString();
+  BOOST_CHECK_EQUAL(face1uri.find("unix:///"), 0); // third '/' is the path separator
+  BOOST_CHECK_EQUAL(face1uri.rfind(CHANNEL_PATH1),
+                    face1uri.size() - std::string(CHANNEL_PATH1).size());
+
   m_face2 = make_shared<UnixStreamFace>(client);
   m_face2->onReceiveInterest +=
     bind(&EndToEndFixture::face2_onReceiveInterest, this, _1);