Add support for CSS modules

[newswim]

We would like to follow a component-folder architecture and having the styles close at hand, and scoped specifically for the component that we're styling is quite helpful. As an illustrative example:

-- /component-name
---- __tests.js
---- actions.js
---- component.js
---- styles.scss
---- reducer.js

Follow one of these guides to add integration:

• https://medium.com/@kswanie21/css-modules-sass-in-create-react-app-37c3152de9
• https://medium.com/nulogy/how-to-use-css-modules-with-create-react-app-9e44bec2b5c2