Summary:
Travis provides a very low capability resource for testing and the
persistent cache tests are too aggressive. It causes the kernel to not have
enough time to do file-system meta data sync operation, causing open file
descriptors to increase and available space to decrease.
This change skips certain tests
Test Plan: Run on travis
Subscribers: leveldb, dhruba, andrewkr
Differential Revision: https://reviews.facebook.net/D61755
59ddb50591