Silence file does not exist error when clearing VK files (#3093)

When clearing VK test files - if some files didn't exist (because they weren't created) the bare rm command will report an error that the files didn't exist. We don't care, only that they are removed if they did exist.

bin/mycroft-skill-testrunner

@@ -31,8 +31,8 @@ function vktest-clear() {
     # A clean directory will have `steps/` and `environment.py`
     if [ "$num_feature_files" -gt "2" ] ; then
         echo "Removing Feature files..."
-        rm "${DIR}"/../test/integrationtests/voight_kampff/features/*.feature
-        rm "${DIR}"/../test/integrationtests/voight_kampff/features/*.config.json
+        rm -f "${DIR}"/../test/integrationtests/voight_kampff/features/*.feature
+        rm -f "${DIR}"/../test/integrationtests/voight_kampff/features/*.config.json
     fi
     STEPS_DIR="$FEATURES_DIR/steps"
     num_steps_files=$(count-files "$STEPS_DIR")
@@ -42,7 +42,7 @@ function vktest-clear() {
         mkdir "$TMP_DIR"
         mv "$STEPS_DIR/configuration.py" "$TMP_DIR"
         mv "$STEPS_DIR/utterance_responses.py" "$TMP_DIR"
-        rm "${STEPS_DIR}"/*.py
+        rm -f "${STEPS_DIR}"/*.py
         mv "${TMP_DIR}"/* "$STEPS_DIR"
         rmdir "$TMP_DIR"
     fi