Install node-gyp version 6.1.0 (#551)

Author: qwu16

docker/Dockerfile

@@ -164,7 +164,7 @@ RUN git config --global user.email "[email protected]" && \
     git clone --depth=1 -b ${OWT_BRANCH} ${OWTSERVER_REPO} && \
 
     # Install node modules for owt
-    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 && \
     cd owt-server && npm install nan && \
 
     # Get openh264 for owt

scripts/installCommonDeps.sh

@@ -362,7 +362,7 @@ 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 [email protected]
   pushd ${ROOT}/node_modules/nan >/dev/null