Bump cornice-swagger from 0.5.4 to 0.7.0

Bumps [cornice-swagger](https://github.com/Cornices/cornice.ext.swagger) from 0.5.4 to 0.7.0.
- [Release notes](https://github.com/Cornices/cornice.ext.swagger/releases)
- [Changelog](https://github.com/Cornices/cornice.ext.swagger/blob/master/CHANGES.rst)
- [Commits](Cornices/cornice.ext.swagger@0.5.4...0.7.0)

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

requirements.txt

@@ -5,7 +5,7 @@ chardet==3.0.4
 colander==1.7.0
 colorama==0.4.1
 cornice==3.5.1
-cornice-swagger==0.5.4
+cornice-swagger==0.7.0
 dockerflow==2018.4.0
 hupper==1.4.2
 idna==2.8