Merge branch '1-change_variable_behaviour' into 'master'

feat: Change boolean variable behaviour

Closes #1

See merge request to-be-continuous/gcloud!1

templates/gitlab-ci-gcloud.yml

@@ -306,7 +306,7 @@ stages:
     fi
   }
 
-  if [[ -z "$TEMPLATE_CHECK_UPDATE_DISABLED" ]]; then check_for_update gcloud "1.3.0"; fi
+  if [[ "$TEMPLATE_CHECK_UPDATE_DISABLED" != "true" ]]; then check_for_update gcloud "1.3.0"; fi
 
   # export tool functions (might be used in after_script)
   export -f log_info log_warn log_error assert_defined awkenvsubst