Automated UI Testing AEM 6.2




I am aware that Calvin has been added to AEM forms 6.3, it looks great for UI testing of AEM forms! Unfortunately the project I am working on is built upon AEM 6.2. Aside from upgrading (not an option), what are my choices for automated testing:

1) Is it possible to include Calvin functionality in AEM 6.2 by installing the calvin library for instance? Or are there technical reasons this would not work?

2) Are there alternatives to Calvin? For instance, has anyone created something custom that they would like to share? Or comment on whether creating something for basic ui testing is actually feasible in 6.2?

3) Are there testing tools external to AEM that are recommended? If so, what are they?

Any thoughts on this gratefully received. Even if they are "can't be done because of X,Y"