Bump pygments from 2.1.3 to 2.7.4

Bumps [pygments](https://github.com/pygments/pygments) from 2.1.3 to 2.7.4.
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](pygments/pygments@2.1.3...2.7.4)

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

requirements.txt

@@ -8,7 +8,7 @@ mock==1.3.0
 nose==1.3.7
 paramiko==2.6.0
 pip>=9.0.1
-pygments==2.1.3
+pygments==2.7.4
 pylint==1.9.3
 pyOpenSSL==19.0.0
 pyyaml==5.1.1