Helpers find/findAll should not be used in user-land test code

[synaptiko]

According to the discussion here emberjs/ember-test-helpers#351 (comment) find/findAll should be avoided. I found the reason here: #6 but maybe it should be mentioned somewhere that it's not recommended way and that one should refactor his code after applying the codemod (or apply the second one and fix the places where this is incorrect).