Updating "productName" parameter to default to "name" value in npm file.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "atom-shell-installer",
-  "version": "0.2.1",
+  "version": "0.2.2",
   "description": "Module to build Windows installers for Atom Shell apps, can be used with Gulp build system.",
   "main": "dist/library-dist.js",
   "scripts": {

src/InstallerFactory.js

@@ -43,7 +43,7 @@ class InstallerFactory {
       this.iconUrl = iconUrl;
       this.description = description || appMetadata.description;
       this.version = version || appMetadata.version;
-      this.productName = appMetadata.productName;
+      this.productName = appMetadata.productName || this.name;
       this.title = title || this.productName || this.name;
       this.certificateFile = certificateFile;
       this.certificatePassword = certificatePassword;

test/unit/InstallerFactory-test.js

@@ -252,12 +252,12 @@ describe('InstallerFactory', () => {
       fs.renameSync.restore();
     });
 
-    it('should resolve without renaming the file if no product name is provieded', (done) => {
+    it('should resolve with renaming the file using name if no product name is provieded', (done) => {
       getPackageJsonStub.returns({author: 'some author', name: 'some name', version: '123', description: 'some desc', productName: undefined});
       let installerFactory = new InstallerFactory({appDirectory: 'correctDir', remoteReleases: 'someUrl'});
       let promise = installerFactory.updateSetupFile();
       promise.then(() => {
-        expect(renameSyncStub.called).to.equal(false);
+        expect(renameSyncStub.calledWith(path.join(installerFactory.outputDirectory, 'Setup.exe'), path.join(installerFactory.outputDirectory, `${installerFactory.productName}Setup.exe`))).to.equal(true);
         done();
       });
     });