Bump traitlets from 5.0.3 to 5.0.4

Bumps [traitlets](https://github.com/ipython/traitlets) from 5.0.3 to 5.0.4.
- [Release notes](https://github.com/ipython/traitlets/releases)
- [Commits](ipython/traitlets@5.0.3...5.0.4)

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

Author: dependabot-preview[bot]

test-requirements.txt

@@ -53,7 +53,7 @@ six==1.15.0               # via astroid, cryptography, packaging, pyopenssl
 sniffio==1.1.0            # via -r test-requirements.in
 sortedcontainers==2.2.2   # via -r test-requirements.in
 toml==0.10.1              # via black, pylint, pytest
-traitlets==5.0.3          # via ipython
+traitlets==5.0.4          # via ipython
 trustme==0.6.0            # via -r test-requirements.in
 typed-ast==1.4.1 ; implementation_name == "cpython"  # via -r test-requirements.in, black, mypy
 typing-extensions==3.7.4.3 ; implementation_name == "cpython"  # via -r test-requirements.in, black, mypy