feat(react-scripts): allow testMatch for jest config (facebook#9114)

resolves facebook#8637

Author: favna

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

@@ -87,6 +87,7 @@ module.exports = (resolve, rootDir, isEjecting) => {
  'resetModules',
  'restoreMocks',
  'snapshotSerializers',
+ 'testMatch',
  'transform',
  'transformIgnorePatterns',
  'watchPathIgnorePatterns',