run CI tests in ChromeHeadless

Author: HackbrettXXX

package.json

@@ -92,7 +92,7 @@
     "version": "yarpm run build && yarpm run generate-docs && git add -A dist docs",
     "pretest": "yarpm run build",
     "test": "yarpm run test-node && yarpm run test-ci",
-    "test-ci": "karma start test/unit/karma.conf.js --single-run --verbose && for a in coverage/*; do codeclimate-test-reporter < \\\"$a/lcov.info\\\"; break; done",
+    "test-ci": "karma start test/unit/karma.conf.js --browsers=ChromeHeadless --single-run --verbose && for a in coverage/*; do codeclimate-test-reporter < \\\"$a/lcov.info\\\"; break; done",
     "test-local": "yarpm run test-unit && yarpm run test-node && yarpm run test-amd && yarpm run test-esm && yarpm run test-globals && yarpm run test-typescript && yarpm run test-webworker",
     "test-unit": "karma start test/unit/karma.conf.js --single-run",
     "test-amd": "karma start test/deployment/amd/karma.conf.js --single-run",