Feature/resolve test error

[ksakiyama]

Hi, @clintonwoo,
Thanks for your awesome React app🎉

This app has two errors on executing npm test. I fixed them. If you like these changes, please merge this Pull Request😀

1. Jest setting is missing

I ran npm test and got the following message.

SecurityError: localStorage is not available for opaque origins

Test Suites: 42 failed, 42 total
Tests:       0 total
Snapshots:   0 total
Time:        1.347s, estimated 4s
Ran all test suites.
npm ERR! Test failed.  See above for more details.

I think that Jest settings are missing. I added "testEnvironment": "node" parameter to package.json.

2. fail to initialize Apollo for testing

After setting testEnvironment, I run npm test again and got the following error message. this.props.serverState.apollo.data isn't initialized.

TypeError: Cannot read property 'data' of undefined

Test Suites: 26 failed, 16 passed, 42 total
Tests:       26 failed, 43 passed, 69 total
Snapshots:   9 passed, 9 total
Time:        4.134s
Ran all test suites.
npm ERR! Test failed.  See above for more details.

I'm not sure is this a coding mistake? I switched to {} from this.props.serverState.apollo.data. I don't know if this chage is a correct fix.

finally

After fixing them, all test passed!

Test Suites: 42 passed, 42 total
Tests:       69 passed, 69 total
Snapshots:   9 passed, 9 total
Time:        3.088s
Ran all test suites.