Only run tests in <rootDir>/src (facebook#544) (facebook#1808)

* Only run tests in <rootDir>/src (facebook#544)

* updates Jest to 19.0.2

* removes testPathIgnorePatterns from jest config

* adds testMatch to jest config to only match files in src

* Bump babel-jest to 19.0.0 to match jest 19.0.2

packages/react-scripts/scripts/utils/createJestConfig.js

@@ -26,19 +26,8 @@ module.exports = (resolve, rootDir, isEjecting) => {
     setupFiles: [resolve('config/polyfills.js')],
     setupTestFrameworkScriptFile: setupTestsFile,
     testMatch: [
-      // Ignore the following directories:
-      // build
-      //   - the build output directory
-      // .cache
-      //   - the yarn module cache on Ubuntu if $HOME === rootDir
-      // docs
-      //   - often used to publish to Github Pages
-      // node_modules
-      //   - ignore tests in dependencies
-      // scripts
-      //   - directory generated upon eject
-      '<rootDir>/!(build|docs|node_modules|scripts)/**/__tests__/**/*.js?(x)',
-      '<rootDir>/!(build|docs|node_modules|scripts)/**/?(*.)(spec|test).js?(x)',
+      '<rootDir>/src/**/__tests__/**/*.js?(x)',
+      '<rootDir>/src/**/?(*.)(spec|test).js?(x)'
     ],
     testEnvironment: 'node',
     testURL: 'http://localhost',