poke: add --verbose option

Change-Id: I435f01cf6625bebbea40a0f808d8456fafb01fe1
diff --git a/tools/peek/ndnpoke/main.cpp b/tools/peek/ndnpoke/main.cpp
index fb26ab0..a327de0 100644
--- a/tools/peek/ndnpoke/main.cpp
+++ b/tools/peek/ndnpoke/main.cpp
@@ -61,6 +61,7 @@
     ("digest,D",    po::bool_switch(&wantDigestSha256),
                     "use DigestSha256 signing method instead of SignatureSha256WithRsa")
     ("timeout,w",   po::value<int>(), "set timeout (in milliseconds)")
+    ("verbose,v",   po::bool_switch(&options.isVerbose), "turn on verbose output")
     ("version,V",   "print version and exit")
   ;