chore(deps): update dependency pygments to v2.7.4

Author: mend-for-github.zerozr99.workers.dev[bot]

requirements.txt

@@ -26,7 +26,7 @@ pluggy==0.7.1
 prompt-toolkit==1.0.15
 ptyprocess==0.6.0
 py==1.6.0
-Pygments==2.2.0
+Pygments==2.7.4
 pyparsing==2.2.0
 pytest==3.8.0
 pytest-cov==2.6.0