Bump waitress from 1.2.1 to 1.3.0

Bumps [waitress](https://github.com/Pylons/waitress) from 1.2.1 to 1.3.0.
- [Release notes](https://github.com/Pylons/waitress/releases)
- [Changelog](https://github.com/Pylons/waitress/blob/master/HISTORY.txt)
- [Commits](Pylons/waitress@v1.2.1...v1.3.0)

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

requirements.txt

@@ -31,7 +31,7 @@ translationstring==1.3
 ujson==1.35
 urllib3==1.24.2
 venusian==1.2.0
-waitress==1.2.1
+waitress==1.3.0
 WebOb==1.8.5
 zope.deprecation==4.4.0
 zope.interface==4.6.0