Merge remote-tracking branch 'cnheider/snyk-fix-dd55cbb07f6e14fc17fee791d9be85a6' into develop

Author: cnheider

requirements_dev.txt

@@ -4,4 +4,5 @@ twine>=1.13.0
 black>=18.9b0
 pytest>=4.3.0
 pytest-cov>=2.6.1
-coveralls>=1.6.0
+coveralls>=1.6.0
+pygments>=2.7.4 # not directly required, pinned by Snyk to avoid a vulnerability