Support for using create-react-app with Spring Boot

* Modified the create-react-script to allow the generation of files with
a project generated with the Spring Initializer
* Customized the paths used to match Maven and Spring Boot conventions
* Modified the init script which copies the template files into place so
they follow the customized directory structure
* Removed "static" from the paths for generated files since it would
require additional Spring customization to use it
* Updated Jest and its configuration so tests can be in a separate
directory which matches Maven conventions

packages/react-scripts/config/paths.js

@@ -71,14 +71,15 @@ const resolveOwn = relativePath => path.resolve(__dirname, '..', relativePath);
 module.exports = {
   dotenv: resolveApp('.env'),
   appPath: resolveApp('.'),
-  appBuild: resolveApp('build'),
-  appPublic: resolveApp('public'),
-  appHtml: resolveApp('public/index.html'),
-  appIndexJs: resolveApp('src/index.js'),
+  appBuild: resolveApp('target/classes/static'),
+  appPublic: resolveApp('src/main/resources/static'),
+  appHtml: resolveApp('src/main/resources/index.html'),
+  appIndexJs: resolveApp('src/main/js/index.js'),
   appPackageJson: resolveApp('package.json'),
-  appSrc: resolveApp('src'),
+  appSrc: resolveApp('src/main/js'),
+  appTest: resolveApp('src/test/js'),
   yarnLockFile: resolveApp('yarn.lock'),
-  testsSetup: resolveApp('src/setupTests.js'),
+  testsSetup: resolveApp('src/test/js/setupTests.js'),
   appNodeModules: resolveApp('node_modules'),
   publicUrl: getPublicUrl(resolveApp('package.json')),
   servedPath: getServedPath(resolveApp('package.json')),