BREAKING CHANGE: changed return array, now it returns only functions in next order: [stop, start, isActive].
Parent component is not re-rendered on loop start/stop.
chore: move all the tests to the separate directory outside of sources;
chore: remove jest.config.js (config moved to the package.json);
test: unused import in test;
test: 💍 fix tests add back x and y to useMeasure
chore: 🤖 add linter to /tests folder
ci: 🎡 limit Jest worker count for CircleCI
