Log Message:
Update to 0.31

Upstream changes:
0.31   2019-01-09

- No changes from 0.30.

0.30   2018-10-08 (TRIAL RELEASE)

- Added an optional feature to track path attribute changes (permissions,
  ownership) as well as to provide the old vs new attributes and/or content in
  modify events. Both of these features are off by default since they can use
  a lot more CPU or memory, especially when using otherwise low-overhead
  kernel-based watchers.