update tests
add tests for AccountsController#deostry
add render_viwes to controller tests
add account for each user, modify user_spec
Merge pull request #3 from mikolajgrzyb/feature/tests

Feature/tests
Merge branch 'develop' of github.com:mikolajgrzyb/timetracker into feature/mark-user

Conflicts:
	app/controllers/invitations_controller.rb
	db/schema.rb
add tests, fixes tests