Install node-gyp version 6.1.0 (#550)

Author: qwu16

scripts/installCommonDeps.sh

@@ -352,7 +352,7 @@ install_node_tools() {
   fi
 
   check_proxy
-  npm install -g --loglevel error node-gyp grunt-cli underscore jsdoc
+  npm install -g --loglevel error node-gyp@6.1.0 grunt-cli underscore jsdoc
   pushd ${ROOT} >/dev/null
   npm install nan@2.11.1
   pushd ${ROOT}/node_modules/nan >/dev/null