build(deps): bump pygments from 2.6.1 to 2.7.4

Bumps [pygments](https://github.com/pygments/pygments) from 2.6.1 to 2.7.4.
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](pygments/pygments@2.6.1...2.7.4)

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

requirements.txt

@@ -29,7 +29,7 @@ pluggy==0.13.1
 py==1.8.1
 pycodestyle==2.5.0
 pyflakes==2.1.1
-Pygments==2.6.1
+Pygments==2.7.4
 pylint==2.4.4
 pyparsing==2.4.6
 pytest==5.4.1