Bump pygments from 2.4.2 to 2.7.4

Bumps [pygments](https://github.com/pygments/pygments) from 2.4.2 to 2.7.4.
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](pygments/pygments@2.4.2...2.7.4)

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

Author: dependabot[bot]

requirements.txt

@@ -25,7 +25,7 @@ pickleshare==0.7.5
 pluggy==0.12.0
 prompt-toolkit==2.0.9
 py==1.8.0
-Pygments==2.4.2
+Pygments==2.7.4
 pyparsing==2.4.0
 pyrsistent==0.14.11
 pytest==5.0.1