Update pre-commit-rubocop

hooks/pre-commit-rubocop

@@ -17,9 +17,9 @@ errors=$(\
     --cpu-shares 1024 \
     --rm=true \
     --volume $app:/app \
-    bbcnews/rubocop-config --format simple --fail-level F 2> /dev/null | grep '^F:\|==' | wc -l)
+    bbcnews/rubocop-config --format simple --fail-level F 2> /dev/null | grep '^F:' | wc -l)
 
 if [ $errors -gt 0 ]; then
-  echo "Rubocop reported errors. Please double check your code"
+  echo "Rubocop reported $errors errors. Please double check your code"
   exit 1
 fi