Migrated tests to jest

Used jest-codemods to migrate, will have to pass everything by hand before we can merge.

test/initialize2DArray/initialize2DArray.js

@@ -1,3 +0,0 @@
-const initialize2DArray = (w, h, val = null) =>
-Array.from({ length: h }).map(() => Array.from({ length: w }).fill(val));
-module.exports = initialize2DArray;