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>

Author: dependabot[bot]

requirements.txt

@@ -6,7 +6,7 @@ docopt-subcommands==3.0.0
 joblib==0.15.1
 jsons==1.1.2
 nltk==3.5
-Pygments==2.6.1
+Pygments==2.7.4
 PyYAML==5.4
 regex==2020.5.14
 tqdm==4.46.0