Replace grunt with npm scripts

test/unit/email-test.js

@@ -1,13 +1,8 @@
 'use strict';
 
-require('co-mocha')(require('mocha')); // monkey patch mocha for generators
-
-const expect = require('chai').expect;
 const log = require('npmlog');
 const Email = require('../../src/email/email');
 const nodemailer = require('nodemailer');
-const sinon = require('sinon');
-
 
 describe('Email Unit Tests', () => {
   let email, sendFnStub;

test/unit/pgp-test.js

@@ -1,11 +1,9 @@
 'use strict';
 
 const fs = require('fs');
-const expect = require('chai').expect;
 const log = require('npmlog');
 const openpgp = require('openpgp');
 const PGP = require('../../src/service/pgp');
-const sinon = require('sinon');
 
 describe('PGP Unit Tests', () => {
   let pgp, key1Armored, key2Armored, key3Armored;

test/unit/util-test.js

@@ -1,6 +1,5 @@
 'use strict';
 
-const expect = require('chai').expect;
 const util = require('../../src/service/util');
 
 describe('Util Unit Tests', () => {