NavBar Component Testing + Snapshots and localStorage Mock

[JosephSemrai]

Created unit test section and initial unit tests regarding the rendering of the component and creating a user.
Snapshot testing (snapshot created in snapshots directory) to which a test will compare itself to the snapshot in the directory.
With this, there is a mock localStorage module that will create an object that behaves like the localStorage API and will assign itself to the window object. This will allow the component to run. There were also a few syntax errors that were corrected in order to run. Given permission, I'd like to open a pull request to address these.
Summary

• Added component tests for NavBar
• Added localStorage mock for NavBar tests (as they are dependent on the user localStorage object)