Bump ipdb from 0.12 to 0.12.1

Bumps [ipdb](https://github.com/gotcha/ipdb) from 0.12 to 0.12.1.
- [Release notes](https://github.com/gotcha/ipdb/releases)
- [Changelog](https://github.com/gotcha/ipdb/blob/master/HISTORY.txt)
- [Commits](gotcha/ipdb@0.12...0.12.1)

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

Author: dependabot-preview[bot]

requirements-dev.txt

@@ -7,7 +7,7 @@ aiopg==0.16.0
 coverage==4.5.3
 docker==4.0.2
 flake8==3.7.8
-ipdb==0.12
+ipdb==0.12.1
 motor==2.0.0
 pytest-cov==2.7.1
 pytest-sugar==0.9.2