Remove xvfb

Author: kum-deepak

.travis.yml

@@ -10,11 +10,6 @@ cache:
 addons:
   chrome: stable
 
-before_install:
-  - export CHROME_BIN=chromium-browser
-  - export DISPLAY=:99.0
-  - sh -e /etc/init.d/xvfb start
-
 script:
   - 'if [ "${D3VER}" = "4" ]; then npm i "d3@^4"; npm list d3; fi'
   - 'if [ "${TRAVIS_PULL_REQUEST}" = "false" ]; then grunt ci; else grunt ci-pull; fi'
@@ -23,6 +18,7 @@ env:
   global:
   - secure: Kt+5IJDJRVwr28xRnmR5YDsJceXDcDR21/JUBfk6DYFixPbIq7LCPnZUmiSZQs8akU95ucXwB5hsirUAdEhXdYKilec6go70lticVlZBLy8IdJ+Di1uPwMOeMHvalC2P0woIRJSMzP8u5E+e+5ASggTjsXID7/p1rE0jXtoOueQ=
   - secure: TED5eLMxEsyIGzKP8xxhyRDbKlIX9POzj1qgan40a8rkwIVzkdglkviLAXJJeP0ilc1GeGz1ctXyA6NAZt7RHB79mdQbH9iV1AsR29ItH4jdBs7eWRybDRKYRlmOntH0n7zlJDB4qQMxvNdI8BKYrPQymgZ3jtRJ/INOvLerg1g=
+  - CHROME_BIN: chromium-browser
   matrix:
   - D3VER: 4
   - D3VER: 5