chore: Cleaned up travis config (#129)

* Removed duplicate `sudo` entry in `.travis.yml`
* Rephrased log message while running cross-browsers integration tests.

.travis.yml

@@ -1,5 +1,4 @@
 language: node_js
-sudo: false
 node_js:
 ## Some of the ES6 syntax used in the browser-polyfill sources is only supported on nodejs >= 6
 ## and the selenium-webdriver dependency used by the integration tests requires nodejs >= 8.
@@ -14,7 +13,7 @@ script:
   ./test/run-module-bundlers-smoketests.sh
 - export DISPLAY=:99.0
 - sh -e /etc/init.d/xvfb start
-- echo "RUN integration tests on chrome" &&
+- echo "RUN integration tests on real browsers" &&
   TRAVIS_CI=true ./test/run-browsers-smoketests.sh
 
 ## See https://docs.travis-ci.com/user/chrome