Install websockets before sockets test run

Author: juj

.circleci/config.yml

@@ -249,6 +249,10 @@ commands:
           command: |
             wget -O ~/chrome.deb https://dl.google.com/linux/direct/google-chrome-beta_current_amd64.deb
             dpkg -i ~/chrome.deb
+      - run:
+          name: install sockets test suite prerequisites
+          command: |
+            npm install ws -g
       - run:
           name: run sockets tests
           environment: