Remove Lodash

[Alex-Cannon]

As @airandfingers pointed out, lodash is used once in the project in the file src/pages/categories/index.jsx. We can easily create a uniqBy utility to replace Lodash's and reduce our package size.

@Vpr99 I'd like your input before we remove this. We may have plans to use Lodash in the future.

[airandfingers]

Note that if we want to keep lodash in, we should use one of a few ways to import that cause Webpack to only include the code that we actually use: https://stackoverflow.com/a/43479515/877682