Bump timecop from 0.9.6 to 0.9.8

Bumps [timecop](https://github.com/travisjeffery/timecop) from 0.9.6 to 0.9.8.
- [Changelog](https://github.com/travisjeffery/timecop/blob/master/History.md)
- [Commits](travisjeffery/timecop@v0.9.6...v0.9.8)

---
updated-dependencies:
- dependency-name: timecop
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile.lock

@@ -428,7 +428,7 @@ GEM
       ruby-graphviz
     thor (1.2.2)
     tilt (2.0.10)
-    timecop (0.9.6)
+    timecop (0.9.8)
     timeout (0.3.2)
     timers (4.3.3)
     traces (0.11.1)