added the path to hydro urdfdom as cmake complain that urdfdom was not found...

added the path to hydro urdfdom as cmake complain that urdfdom was not found in the jrl-walkgen compilation

travis_custom/custom_build

@@ -8,6 +8,13 @@ set -v
 # Setup environment variables.
 export CMAKE_ADDITIONAL_OPTIONS=" ${CMAKE_ADDITIONAL_OPTIONS} -DBUILD_UNIT_TESTS=\"ON\""
 
+export PKG_CONFIG_PATH="${PKG_CONFIG_PATH}:/opt/openrobots/lib/pkgconfig"
+export LD_LIBRARY_PATH="${LD_LIBRARY_PATH}:/opt/openrobots/lib"
+
+export PKG_CONFIG_PATH="${PKG_CONFIG_PATH}:/opt/ros/hydro/lib/pkgconfig"
+export LD_LIBRARY_PATH="${LD_LIBRARY_PATH}:/opt/ros/hydro/lib"
+
+
 # Setup environment variables.
 . ./.travis/run ../.travis/build