updating devDependencies and applying changes to code (jest config)

```
npm i -D @babel/cli@latest @babel/core@latest @babel/preset-env@latest \
    @babel/preset-react@latest babel-jest@latest cross-env@latest \
    eslint@latest eslint-config-airbnb@latest eslint-plugin-import@latest \
    eslint-plugin-jsx-a11y@latest eslint-plugin-react@latest jest@latest \
    react@latest react-dom@latest react-test-renderer@latest \
    regenerator-runtime@latest rollup@latest vue@latest vuex@latest
```

- added testEnvironment config to jest