Things to install:
//babel
npm install --save-dev @babel/core @babel/preset-env @babel/node
--> then create a file called .babelrc in the root of your project
--> INSIDE the .babelrc file, add this:
{ "presets": ["@babel/preset-env"] }
THEN...
npm i jest --save installs and saves jest to dependencies
npm i supertest --save installs and saves supertest to dependencies
npm i @babel/polyfill --save-dev installs and saves babel polyfill to dev dependencies
npm i babel-core --save-dev installs and saves babel-core to dev dependencies (DIFFERENT from the @babel/core that gets installed when you install babel)
npm i nodemon --save-dev installs nodemon to dev dependencies. doesn't seem to have anything to do with testing but who knows
npm i regenerator-runtime --save-dev