Bump pyyaml from 5.3.1 to 5.4

Bumps [pyyaml](https://github.com/yaml/pyyaml) from 5.3.1 to 5.4.
- [Release notes](https://github.com/yaml/pyyaml/releases)
- [Changelog](https://github.com/yaml/pyyaml/blob/master/CHANGES)
- [Commits](yaml/pyyaml@5.3.1...5.4)

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

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

Author: dependabot[bot]

Pipfile

@@ -25,7 +25,7 @@ pytest-notebook = "==0.6.0"
 PrettyTable = "==0.7.2"
 PyICU = "==2.5"
 Morfessor = "==2.0.6"
-PyYAML = "==5.3.1"
+PyYAML = "==5.4"
 fire = "*"
 pytz = "*"
 pipenv-shebang = "*"