styling in react: styled-components is already in the package.json

[jsms90]

In the latest commit, styled-components was added to the package.json along with the updated version of react.

This makes part 1 of the exercise unnecessary:

Part 1, install styled-components

styled-components is a npm package which we need to add to our project

 npm install --save styled-components

but it's nice to get everyone to explicitly install styled-components, so maybe it could be removed from the package.json again?