replace phantom js with headless chrome

.travis.yml

@@ -1,5 +1,8 @@
 language: node_js
+dist: trusty
 node_js:
-  - '6'
+  - '9'
+addons:
+  chrome: stable
 after_success:
   - npm run coverage

package.json

@@ -26,11 +26,11 @@
 		"chai": "^3.5.0",
 		"eslint": "^3.11.0",
 		"karma": "^1.3.0",
+		"karma-chrome-launcher": "^2.2.0",
 		"karma-coverage": "^1.1.1",
 		"karma-coveralls": "^1.1.2",
 		"karma-mocha": "^1.3.0",
 		"karma-mocha-reporter": "^2.2.0",
-		"karma-phantomjs-launcher": "^1.0.2",
 		"karma-rollup-preprocessor": "^5.0.1",
 		"karma-sauce-launcher": "^1.1.0",
 		"karma-sinon-chai": "^1.2.4",

test/karma.conf.js

@@ -1,5 +1,3 @@
-process.env.PHANTOMJS_BIN = './node_modules/phantomjs-prebuilt/bin/phantomjs'
-
 const rollupPlugins = [require('rollup-plugin-buble')()]
 
 if (!process.env.TRAVIS || process.env.COVERAGE) {
@@ -45,7 +43,7 @@ module.exports = function(karma) {
 		if (process.env.COVERAGE) {
 			karma.set({
 				autoWatch: false,
-				browsers: ['PhantomJS'],
+				browsers: ['ChromeHeadless'],
 				coverageReporter: {
 					type: 'lcovonly',
 					dir: 'coverage/'
@@ -73,7 +71,7 @@ module.exports = function(karma) {
 		}
 	} else {
 		karma.set({
-			browsers: ['PhantomJS'],
+			browsers: ['ChromeHeadless'],
 			coverageReporter: {
 				type: 'lcov',
 				dir: '../.ignore/coverage/'