Replace mocha with Jest

[just4fun]

[just4fun]

This tech debt is blocked by

• Updating master to support react > 16 + native > 0.52 RealOrangeOne/react-native-mock#158
• Create Adapter for React Native & React 16 enzymejs/enzyme#1436

One possible workaround is https://stackoverflow.com/questions/42039383/how-to-use-enzyme-for-react-native-with-jest.

Exclude this ticket from v1.7.0 until there is better solution.