Update cornice requirement from <6,>=5.0.3 to >=5.0.3,<7

Updates the requirements on [cornice](https://github.com/mozilla-services/cornice) to permit the latest version.
- [Release notes](https://github.com/mozilla-services/cornice/releases)
- [Changelog](https://github.com/Cornices/cornice/blob/master/CHANGES.txt)
- [Commits](Cornices/cornice@5.0.3...6.0.1)

---
updated-dependencies:
- dependency-name: cornice
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

setup.py

@@ -33,7 +33,7 @@
     'six>=1.15.0',
     'pyramid==1.10.8',
     'pyramid_jinja2>=2.8,<3',
-    'cornice>=5.0.3,<6',
+    'cornice>=5.0.3,<7',
     'simplejson>=3.17.2,<4',
     'Jinja2<4',
     'munch>=2.5.0,<3',