Migrated tests to jest

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

test/randomHexColorCode/randomHexColorCode.js

@@ -1,5 +0,0 @@
-const randomHexColorCode = () => {
-let n = (Math.random() * 0xfffff * 1000000).toString(16);
-return '#' + n.slice(0, 6);
-};
-module.exports = randomHexColorCode;