Fix non-parallel option changelog entry
### Features
- Run hooks in parallel
- - individual hooks may opt out of parallel exection with `parallel: false`
+ - individual hooks may opt out of parallel exection with `require_serial: true`
- #510 issue by @chriskuehl.
- #851 PR by @chriskuehl.
- #885 PR by @s0undt3ch.
### Updating
-- If a hook requires serial execution, set `parallel: false` to avoid the new
+- If a hook requires serial execution, set `require_serial: true` to avoid the new
parallel execution.
- `ruby` hooks now require `gem>=2.0.0`. If your platform doesn't support this
by default, select a newer version using
