test: use dirty-chai

Author: daviddias

package.json

@@ -39,6 +39,7 @@
   "devDependencies": {
     "aegir": "^11.0.0",
     "chai": "^3.5.0",
+    "dirty-chai": "^1.2.2",
     "pre-commit": "^1.2.2"
   },
   "homepage": "https://github.com/multiformats/js-multihashing",

test/index.spec.js

@@ -1,7 +1,10 @@
 /* eslint-env mocha */
 'use strict'
 
-const expect = require('chai').expect
+const chai = require('chai')
+const dirtyChai = require('dirty-chai')
+chai.use(dirtyChai)
+const expect = chai.expect
 const multihashing = require('../src')
 
 describe('multihashing', () => {