dillon1000/react

[housekeeping] Remove disabled test262 setup

I sincerely appreciate the effort to get test262 up and running. This was my 
idea, it seemed like a really good way to test our correctness on edge cases of 
JS. Unfortunately test262 relies heavily on a few specific features that we 
don't support, like classes and `var`, which has meant that we never actually 
use this as a test suite. 

In the meantime we've created a pretty extensive test suite and have tools like 
Sprout to test actual memoization behavior at runtime, which is the right place 
to invest our energy. Let's remove?