Start xvfb on linux.

.travis.yml

@@ -1,10 +1,15 @@
 language: node_js
 
+before_script:
+  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then export DISPLAY=:99.0; sh -e /etc/init.d/xvfb start; fi
+
 matrix:
   include:
     - os: linux
       sudo: required
       dist: trusty
+    - os: osx
+      osx_image: xcode7.3
 
 cache:
   directories:

package.json

@@ -77,7 +77,7 @@
     "prestart": "npm install && npm run compile",
     "start": "concurrently --kill-others -s first \"tsc --watch\" \"cross-env NODE_ENV=development npm run electron\"",
     "test": "npm run lint && npm run compile && npm run unit-tests && npm run ui-tests && npm run integration-tests",
-    "unit-tests": "find test -name '*_spec.ts'",
+    "unit-tests": "electron-mocha --require ts-node/register $(find test -name '*_spec.ts')",
     "ui-tests": "electron-mocha --require ts-node/register $(find test -name '*_spec.tsx')",
     "integration-tests": "electron-mocha --require ts-node/register test/e2e.ts",
     "update-dependencies": "ncu -u",