Adding override options to Jest

Similar to Create React App, you can now override the following Jest options:

'collectCoverageFrom',
'coverageReporters',
'coverageThreshold',
'extraGlobals',
'globalSetup',
'globalTeardown',
'resetMocks',
'resetModules',
'setupFilesAfterEnv',
'snapshotSerializers',
'transform',
'transformIgnorePatterns',
'watchPathIgnorePatterns',