Merge #7

7: Pin circleci/node Docker tag r=mythmon a=renovate[bot]

This Pull Request pins Docker base image `circleci/node:9` to use a digest (`sha256:893f76a757ef2bbd939a655ba416943b60b33e4f3946e79ce1007e25925c1f19`).
This digest will then be kept updated via Pull Requests whenever the image is updated on the Docker registry. For details on Renovate's Docker support, please visit https://renovateapp.com/docs/language-support/docker


**Important**: Renovate will wait until you have merged this Pin request before creating PRs for any *upgrades*. If you do not wish to pin anything, please update your config accordingly instead of leaving this PR open.



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This PR has been generated by [Renovate Bot](https://renovateapp.com).

Co-authored-by: Renovate Bot <bot@renovateapp.com>

.circleci/config.yml

@@ -3,7 +3,7 @@ version: 2
 jobs:
   build_test:
     docker:
-      - image: circleci/node:9
+      - image: circleci/node:9@sha256:893f76a757ef2bbd939a655ba416943b60b33e4f3946e79ce1007e25925c1f19
 
     steps:
       - checkout