issues/51 - Fix test script

[dangleit01]

When I ran command "npm test", I received error:

Pattern: jest.config.js - 0 matches
npm ERR! Test failed.
The current test script is described as

"test": "jest --config --runInBand jest.config.js"
To fix it, I changed the script to:

"test": "jest --config jest.config.js --runInBand"