ci: workflow for caching of binder build added.

.github/workflows/binder.yml

@@ -0,0 +1,15 @@
+name: binder
+on:
+  push:
+    branches:
+      - develop
+
+jobs:
+  Create-MyBinderOrg-Cache:
+    runs-on: ubuntu-latest
+    steps:
+    - name: cache binder build on mybinder.org
+      uses: jupyterhub/repo2docker-action@master
+      with:
+        NO_PUSH: true
+        MYBINDERORG_TAG: ${{ github.event.ref }} # This builds the container on mybinder.org with the branch that was pushed on.