add edge 15, use chrome stable

.travis.yml

@@ -1,27 +1,20 @@
 language: node_js
-sudo: required
+sudo: false
 dist: trusty
 node_js: stable
 addons:
   firefox: latest
-  apt:
-    sources:
-    - google-chrome
-    packages:
-    - google-chrome-beta
+  chrome: stable
 cache:
   directories:
   - node_modules
 before_script:
-- mkdir -p ~/bin
-- ln -s /usr/bin/google-chrome-beta ~/bin/google-chrome
-- export PATH=$HOME/bin:$PATH
 - npm install -g bower gulp-cli@1
 - bower install
 - gulp lint-eslint
 script:
 - xvfb-run wct
-- if [ "${TRAVIS_PULL_REQUEST}" = "false" ]; then wct -s 'windows 10/microsoftedge@14' -s 'windows 8.1/internet explorer@11' -s 'os x 10.11/safari@9' -s 'macos 10.12/safari@10' -s 'Linux/chrome@41'; fi
+- if [ "${TRAVIS_PULL_REQUEST}" = "false" ]; then wct -s 'windows 10/microsoftedge@14' -s 'windows 10/microsoftedge@15' -s 'windows 8.1/internet explorer@11' -s 'os x 10.11/safari@9' -s 'macos 10.12/safari@10' -s 'Linux/chrome@41'; fi
 env:
   global:
   - secure: bfF/o1ewpOxDNqTzWfvlwgRgGfP8OXhSQLLdEwZ6izO9tckMJuSNghk3qBXCEQJwTcUEyXP6EqfzIrRAvDXPa0H3OoinbrooDyV2wIDaVRK++WR2iZIqzqo3hGOdzm4tdrGJZe5av5Rk661Hls8aPfLbjdzcGuYXi8B4wZq2xMI=