Integrate travis and coveralls

.nycrc.json

@@ -0,0 +1,4 @@
+{
+  "include": "index.js",
+  "reporter": "text-summary"
+}

.travis.yml

@@ -0,0 +1,11 @@
+language: node_js
+node_js:
+- '8'
+- '10'
+- '11'
+- '12'
+cache: yarn
+script:
+  - yarn lint
+  - yarn test
+after_success: 'yarn coveralls'

package.json

@@ -6,10 +6,12 @@
   "scripts": {
     "release": "release-it",
     "lint": "standard -v",
-    "test": "mocha"
+    "test": "nyc mocha",
+    "cover:report": "nyc report --reporter=html && open-cli ./coverage/index.html",
+    "coveralls": "nyc report --reporter=text-lcov | coveralls"
   },
   "engines": {
-    "node": ">=7.0.0"
+    "node": ">=8.0.0"
   },
   "repository": {
     "type": "git",
@@ -29,10 +31,15 @@
   ],
   "devDependencies": {
     "chai": "^4.2.0",
+    "chai-datetime": "^1.5.0",
+    "coveralls": "^3.0.6",
     "dirty-chai": "^2.0.1",
     "mocha": "^6.2.0",
+    "nyc": "^14.1.1",
+    "open-cli": "^5.0.0",
     "release-it": "^12.3.5",
-    "sinon": "^7.4.1"
+    "sinon": "^7.4.1",
+    "standard": "^13.1.0"
   },
   "standard": {
     "env": {