features: config options, saving to file, SARIF

- Upgrade to Hadolint 2.8.0, enabling the SARIF formatter
- Expand config options to reflect more of those regularly available
  with Hadolint including `no-fail` and `failure-threshold` options
- Enable the creation of report files

Breaking change: The list of ignored rules is now comma separated and
not space separated.

fixes: #23
fixes: #36
fixes: #42

hadolint.sh

@@ -23,9 +23,13 @@ if [ -n "$HADOLINT_CONFIG" ]; then
   HADOLINT_CONFIG="-c ${HADOLINT_CONFIG}"
 fi
 
-for i in $HADOLINT_IGNORE; do
-  HADOLINT_IGNORE_CMDLINE="${HADOLINT_IGNORE_CMDLINE} --ignore=${i}"
-done
+OUTPUT=
+if [ -n "$HADOLINT_OUTPUT" ]; then
+  if [ -f "$HADOLINT_OUTPUT" ]; then
+    HADOLINT_OUTPUT="$TMP_FOLDER/$HADOLINT_OUTPUT"
+  fi
+  OUTPUT=" | tee $HADOLINT_OUTPUT"
+fi
 
 if [ "$HADOLINT_RECURSIVE" = "true" ]; then
   shopt -s globstar
@@ -33,8 +37,10 @@ if [ "$HADOLINT_RECURSIVE" = "true" ]; then
   filename="${!#}"
   flags="${@:1:$#-1}"
 
-  hadolint $HADOLINT_IGNORE_CMDLINE $HADOLINT_CONFIG $flags **/$filename
+  hadolint $HADOLINT_CONFIG $flags **/$filename $OUTPUT
 else
   # shellcheck disable=SC2086
-  hadolint $HADOLINT_IGNORE_CMDLINE $HADOLINT_CONFIG "$@"
+  hadolint $HADOLINT_CONFIG "$@" $OUTPUT
 fi
+
+[ -z "$HADOLINT_OUTPUT" ] || echo "Hadolint output saved to: $HADOLINT_OUTPUT"