Deploy carbonplan hub automatically

Ref 2i2c-org#507

I'm worried that incomplete tests might leave notebook
nodes running, but the culler should take care of those? We
must verify this.

The creds for the carbonplan cluster are from EKS,
and I'm not sure how long they are valid for either.

.github/workflows/deploy-carbonplan.yaml

@@ -0,0 +1,30 @@
+name: Deploy and Test carbonplan hub
+
+on:
+  push:
+    branches: [ master ]
+    paths:
+      - deployer/**
+      - hub-templates/**
+      - requirements.txt
+      - dev-requirements.txt
+      - config/secrets.yaml
+      - config/hubs/carbonplan.cluster.yaml
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: google-github-actions/setup-gcloud@master
+        with:
+          version: '290.0.1'
+          # This is used for KMS only
+          project_id: two-eye-two-see
+          service_account_key: ${{ secrets.GCP_KMS_DECRYPTOR_KEY }}
+          export_default_credentials: true
+      - uses: azure/setup-helm@v1
+      - uses: mdgreenwald/mozilla-sops-action@v1
+      - uses: ./.github/actions/deploy
+        with:
+          cluster: 'carbonplan'