Limit some .gitignore patterns
Limit some .gitignore patterns

Summary:
These patterns are just meant to ignore stuff in the root directory of
redex, but they weren't properly anchored, so we were ignoring everything under
"tools/redex-all", since "redex-all" was listed as a pattern.  This manifested
hilariously for me as wasting a good 30 minutes wondering why my fancy
.gitignore-aware grep wasn't finding stuff it should have.

Reviewed By: int3

Differential Revision: D3582618

fbshipit-source-id: 534a4b366026d2804342e4658ff06af602dd1d48

facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex