Test adjustments and improvements.

* Reducing code duplication
* Using import destructuring.
* Ignoring integration test file output.
* Changing package 'test' script to not use hashbang execution.
* Explicitly requiring jake rather than relying on global import
* Fixing integration tests to run on Windows.

Author: Tzrlk

package-lock.json

@@ -17,7 +17,7 @@
   "scripts": {
     "lint": "eslint --format codeframe \"lib/**/*.js\" \"test/**/*.js\"",
     "lint:fix": "eslint --fix \"lib/**/*.js\" \"test/**/*.js\"",
-    "test": "./bin/cli.js test",
+    "test": "node ./bin/cli.js test",
     "test:ci": "npm run lint && npm run test"
   },
   "repository": {

package.json

@@ -0,0 +1,3 @@
+*.txt
+*.json
+*.tar.gz

test/integration/.gitignore

@@ -1,41 +1,38 @@
 let assert = require('assert');
-let exec = require('child_process').execSync;
-
-const PROJECT_DIR = process.env.PROJECT_DIR;
-const JAKE_CMD = `${PROJECT_DIR}/bin/cli.js`;
+let { execJake } = require('./helpers')
 
 suite('concurrent', function () {
 
   this.timeout(7000);
 
   test(' simple concurrent prerequisites 1', function () {
-    let out = exec(`${JAKE_CMD} -q concurrent:simple1`).toString().trim()
+    let out = execJake('-q concurrent:simple1')
     assert.equal('Started A\nStarted B\nFinished B\nFinished A', out);
   });
 
   test(' simple concurrent prerequisites 2', function () {
-    let out = exec(`${JAKE_CMD} -q concurrent:simple2`).toString().trim()
+    let out = execJake('-q concurrent:simple2')
     assert.equal('Started C\nStarted D\nFinished C\nFinished D', out);
   });
 
   test(' sequential concurrent prerequisites', function () {
-    let out = exec(`${JAKE_CMD} -q concurrent:seqconcurrent`).toString().trim()
+    let out = execJake('-q concurrent:seqconcurrent')
     assert.equal('Started A\nStarted B\nFinished B\nFinished A\nStarted C\nStarted D\nFinished C\nFinished D', out);
   });
 
   test(' concurrent concurrent prerequisites', function () {
-    let out = exec(`${JAKE_CMD} -q concurrent:concurrentconcurrent`).toString().trim()
+    let out = execJake('-q concurrent:concurrentconcurrent')
     assert.equal('Started A\nStarted B\nStarted C\nStarted D\nFinished B\nFinished C\nFinished A\nFinished D', out);
   });
 
   test(' concurrent prerequisites with subdependency', function () {
-    let out = exec(`${JAKE_CMD} -q concurrent:subdep`).toString().trim()
+    let out = execJake('-q concurrent:subdep')
     assert.equal('Started A\nFinished A\nStarted Ba\nFinished Ba', out);
   });
 
   test(' failing in concurrent prerequisites', function () {
     try {
-      exec(`${JAKE_CMD} -q concurrent:Cfail`);
+      execJake('-q concurrent:Cfail');
     }
     catch(err) {
       assert(err.message.indexOf('Command failed') > -1);