Summary:
The folly version which we were using to build open source was v2018.08.06.00, which is very outdated.
This PR updates the version of the folly to the latest one.
Pull Request resolved: https://github.com/facebook/flipper/pull/355
Reviewed By: passy
Differential Revision: D13710812
Pulled By: priteshrnandgaonkar
fbshipit-source-id: 62b205d10c18f4338ead69612b24805c697081fb
