gh-actions: testing in several python versions

.github/workflows/test.yml

@@ -4,16 +4,20 @@ on: [push, pull_request]
 env:
   EMG_CONFIG: ${{ github.workspace }}/ci/configuration.yaml
 
+strategy:
+  matrix:
+    python-version: [3.4, 3.5, 3.6]
+
 jobs:
   build:
 
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
-    - name: 🐍 - Set up Python 3.6
+    - name: 🐍 - Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v2
       with:
-        python-version: '3.6'
+        python-version:  ${{ matrix.python-version }}
     - name: 💾 Start MongoDB
       uses: supercharge/[email protected]
       with:
@@ -48,7 +52,7 @@ jobs:
     - name: 📮 - Slack Notification
       uses: rtCamp/action-slack-notify@v2
       continue-on-error: true
-      if: github.ref == 'refs/heads/master' || github.ref == 'refs/heads/dev'
+      if: github.ref == 'refs/heads/master' || github.ref == 'refs/heads/develop'
       env:
         SLACK_COLOR: "${{ job.status == 'success' && 'good' || 'danger' }}"
         SLACK_USERNAME: "Github Actions API"