The visual regression test repo currently contains several files that have logic that are not test files (e.g. checking out branches, etc) and are not currently unit tested. We'll also most likely be adding more logic to this repo. Adding Jest was a huge improvement in the Vector codebase and this ticket proposes we add Jest and add at least 1 test to the Pixel repo which will enable us to add more unit tests in the future.

Acceptance Criteria

• Jest is added to Pixel with code coverage reports for the JS files in the src directory (excluding the visual regression tests) when npm run test is run

Developer notes

Mostly done. See https://github.com/nicholasray/pixel/pull/6