Add discover binary to fabric-tools image

FAB-11316 #done
add discover binary to fabric-tools image

Change-Id: I8f7f534ed4ae91ffd52ae6d4de214dc5fb48d7ad
Signed-off-by: Christopher Ferris <chrisfer@us.ibm.com>

Author: christo4ferris

images/tools/Dockerfile.in

@@ -8,7 +8,7 @@ RUN mkdir src && mkdir pkg && mkdir bin
 ADD . src/github.com/hyperledger/fabric
 WORKDIR /opt/gopath/src/github.com/hyperledger/fabric
 ENV EXECUTABLES go git curl
-RUN make configtxgen configtxlator cryptogen peer
+RUN make configtxgen configtxlator cryptogen peer discover
 
 FROM _BASE_NS_/fabric-baseimage:_BASE_TAG_
 ENV FABRIC_CFG_PATH /etc/hyperledger/fabric