Bump pygments from 2.5.2 to 2.7.4

Bumps [pygments](https://github.com/pygments/pygments) from 2.5.2 to 2.7.4.
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](pygments/pygments@2.5.2...2.7.4)

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

requirements-dev.txt

@@ -26,7 +26,7 @@ pudb==2019.2
 py==1.8.0
 pycodestyle==2.5.0
 pyflakes==2.1.1
-Pygments==2.5.2
+Pygments==2.7.4
 pylint==2.4.4
 pyparsing==2.4.5
 pytest==5.3.2