Bump cornice from 3.5.1 to 3.6.0

Bumps [cornice](https://github.com/mozilla-services/cornice) from 3.5.1 to 3.6.0.
- [Release notes](https://github.com/mozilla-services/cornice/releases)
- [Changelog](https://github.com/Cornices/cornice/blob/master/CHANGES.txt)
- [Commits](Cornices/cornice@3.5.1...3.6.0)

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

requirements.txt

@@ -4,7 +4,7 @@ cffi==1.12.3
 chardet==3.0.4
 colander==1.7.0
 colorama==0.4.1
-cornice==3.5.1
+cornice==3.6.0
 cornice-swagger==0.7.0
 dockerflow==2019.6.0
 hupper==1.8.1