Bump colander from 1.8.2 to 1.8.3

Bumps [colander](https://github.com/Pylons/colander) from 1.8.2 to 1.8.3.
- [Release notes](https://github.com/Pylons/colander/releases)
- [Changelog](https://github.com/Pylons/colander/blob/master/CHANGES.rst)
- [Commits](Pylons/colander@1.8.2...1.8.3)

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

Author: dependabot-preview[bot]

requirements.txt

@@ -4,7 +4,7 @@ boto==2.49.0
 certifi==2020.6.20
 cffi==1.14.1
 chardet==3.0.4
-colander==1.8.2
+colander==1.8.3
 colorama==0.4.3
 cornice==5.0.3
 cornice-swagger==1.0.0