Remove exists-sync dependency

(cherry picked from commit f1cada5)

lib/calculate-version.js

@@ -1,5 +1,5 @@
 var path = require('path');
-var existsSync = require('exists-sync');
+var fs = require('fs');
 var gitRepoInfo = require('git-repo-info');
 var npmGitInfo = require('npm-git-info');
 
@@ -9,7 +9,7 @@ module.exports = function() {
   var packageVersion = package.version;
   var suffix = '';
 
-  if (existsSync(gitPath)) {
+  if (fs.existsSync(gitPath)) {
     var info = gitRepoInfo(gitPath);
     if (info.tag) {
       return info.tag.replace(/^v/, '');

lib/utilities/extend-from-application-entity.js

@@ -1,7 +1,7 @@
 var stringUtil  = require('ember-cli-string-utils');
 var SilentError = require('silent-error');
 var pathUtil    = require('ember-cli-path-utils');
-var existsSync  = require('exists-sync');
+var fs  = require('fs');
 var path        = require('path');
 
 module.exports = function(type, baseClass, options) {
@@ -15,7 +15,7 @@ module.exports = function(type, baseClass, options) {
 
   var entityDirectory = type + 's';
   var applicationEntityPath = path.join(options.project.root, 'app', entityDirectory, 'application.js');
-  var hasApplicationEntity = existsSync(applicationEntityPath);
+  var hasApplicationEntity = fs.existsSync(applicationEntityPath);
   if (!isAddon && !options.baseClass && entityName !== 'application' && hasApplicationEntity) {
     options.baseClass = 'application';
   }

package.json

@@ -43,7 +43,6 @@
     "ember-cli-version-checker": "^2.1.0",
     "ember-inflector": "^2.0.0",
     "ember-runtime-enumerable-includes-polyfill": "^2.0.0",
-    "exists-sync": "0.0.3",
     "git-repo-info": "^1.1.2",
     "heimdalljs": "^0.3.0",
     "inflection": "^1.8.0",