test(ci): update travis config

.gitignore

@@ -1,7 +1,7 @@
-logs
-*.log
-node_modules
+.DS_Store
 .idea
+*.log*
+node_modules
 /lib
 /es
-npm-debug.log*
+/coverage

.travis.yml

@@ -1,12 +1,10 @@
 language: node_js
 node_js:
-  - stable
-cache:
-  directories:
-    - node_modules
-before_install:
-  - export CHROME_BIN=chromium-browser
-  - export DISPLAY=:99.0
-  - sh -e /etc/init.d/xvfb start
+  - '6'
+  - '7'
+  - '8'
 script:
-  - npm run test
+  - yarn run fmt:check
+  - yarn run test:cover
+#after_success:
+#  - yarn run coverage

package.json

@@ -60,14 +60,16 @@
   "jsnext:main": "es/index.js",
   "scripts": {
     "test": "npm run test:unit",
+    "test:cover": "npm run test:unit:cover",
     "test:unit": "jest --verbose ./test",
+    "test:unit:cover": "jest --verbose --coverage ./test",
     "build:commonjs": "cross-env NODE_ENV=commonjs babel src --out-dir lib",
     "build:es": "cross-env NODE_ENV=es babel src --out-dir es",
     "build": "npm run build:commonjs && npm run build:es",
     "fmt": "prettier --print-width=100 --tab-width=4 --bracket-spacing --no-semi --trailing-comma es5 --single-quote --color --write \"{src,specs,test}/**/*.js\"",
     "fmt:check": "prettier --print-width=100 --tab-width=4 --bracket-spacing --no-semi --trailing-comma es5 --single-quote --list-different \"{src,specs,test}/**/*.js\"",
     "version": "echo ${npm_package_version}",
-    "prebublishOnly": "npm run build",
+    "prebublishOnly": "npm test && npm run build",
     "precommit": "lint-staged",
     "commitmsg": "validate-commit-msg"
   },