update patch version of flake8 in pre-commit config

Author: jbweston

.pre-commit-config.yaml

@@ -10,7 +10,7 @@ repos:
     -   id: end-of-file-fixer
     -   id: trailing-whitespace
 -   repo: https://gitlab.com/pycqa/flake8
-    rev: 3.7.4
+    rev: 3.7.8
     hooks:
     -   id: flake8
         args: ['--max-line-length=500', '--ignore=E203,E266,E501,W503', '--max-complexity=18', '--select=B,C,E,F,W,T4,B9']