chore(deps): update node:8.16.0 docker digest to d16c9fc

Author: renovate-bot

.circleci/config.yml

@@ -6,7 +6,7 @@ machine:
 jobs:
   build:
     docker:
-      - image: node:8.16.0@sha256:37ecd6c3ab4857cd1a489ce972de69bd7585e665ba1e524e8d9b5bb36a9981f6
+      - image: node:8.16.0@sha256:d16c9fcf0b4f219aad05d74ffeeed7a56874c2737b19c06887771634204224c4
     environment:
       - NPM_CONFIG_LOGLEVEL: warn
     working_directory: ~/repo