CI: Exclude asv benchmark envs from flake8 checks

Author: qwhelan

ci/code_checks.sh

@@ -31,9 +31,12 @@ if [[ -z "$CHECK" || "$CHECK" == "lint" ]]; then
     echo "flake8 --version"
     flake8 --version
 
+    # Add asv env directory to flake8 default exclude list
+    FLAKE8_EXCLUDES=".svn,CVS,.bzr,.hg,.git,__pycache__,.tox,.eggs,*.egg,env"
+
     # pandas/_libs/src is C code, so no need to search there.
     MSG='Linting .py code' ; echo $MSG
-    flake8 .
+    flake8 --exclude $FLAKE8_EXCLUDES .
     RET=$(($RET + $?)) ; echo $MSG "DONE"
 
     MSG='Linting .pyx code' ; echo $MSG