Add coverage tests

Author: wooorm

.gitignore

@@ -1,4 +1,6 @@
 .DS_Store
 *.log
-/node_modules/
+.nyc_output/
+coverage/
+node_modules/
 yarn.lock

.prettierignore

@@ -0,0 +1 @@
+coverage/

.travis.yml

@@ -2,3 +2,4 @@ language: node_js
 node_js:
 - lts/boron
 - node
+after_script: bash <(curl -s https://codecov.io/bash)

package.json

@@ -29,6 +29,7 @@
     "object-assign": "^4.1.0"
   },
   "devDependencies": {
+    "nyc": "^12.0.2",
     "prettier": "^1.14.2",
     "remark-cli": "^5.0.0",
     "remark-preset-wooorm": "^4.0.0",
@@ -37,7 +38,15 @@
   },
   "scripts": {
     "format": "remark . -qfo && prettier --write \"**/*.js\" && xo --fix",
-    "test": "node test"
+    "test-api": "node test",
+    "test-coverage": "nyc --reporter lcov tape test.js",
+    "test": "npm run format && npm run test-coverage"
+  },
+  "nyc": {
+    "check-coverage": true,
+    "lines": 100,
+    "functions": 100,
+    "branches": 100
   },
   "prettier": {
     "tabWidth": 2,

test.js

@@ -1,8 +1,7 @@
 'use strict'
 
-var u = require('..')
-
 var test = require('tape')
+var u = require('.')
 
 test(function(t) {
   t.deepEqual(