skip flake8 for existing files and unit tests

Author: truib

.flake8

@@ -7,8 +7,15 @@
 #
 
 [flake8]
-max-line-length = 120
+exclude =
+    scripts/check-stratum-servers.py,
+    scripts/automated_ingestion/automated_ingestion.py,
+    scripts/automated_ingestion/eessitarball.py,
+    scripts/automated_ingestion/utils.py,
+    scripts/automated_ingestion/unit_tests/*.py
 
 # ignore "Black would make changes" produced by flake8-black
 # see also https://github.com/houndci/hound/issues/1769
 extend-ignore = BLK100
+
+max-line-length = 120