Merge pull request 'add ci/cd conf (drone)' (#71) from develop into master

Reviewed-on: #71

.drone.yml

@@ -0,0 +1,36 @@
+---
+kind: pipeline
+type: docker
+name: default
+
+steps:
+  - name: dependencies
+    image: deblan/devenv
+    commands:
+      - npm install
+    when:
+      event:
+        - push
+
+  - name: build
+    image: deblan/devenv
+    volumes:
+      - name: artefacts
+        path: /artefacts
+    environment:
+      APP_CERTIFICATE:
+        from_secret: app_certificate
+    commands:
+      - mkdir -p "$HOME/.nextcloud/certificates"
+      - echo "$APP_CERTIFICATE" > "$HOME/.nextcloud/certificates/side_menu.key"
+      - export VERSION=$(grep "<version>" appinfo/info.xml | grep -o "[0-9]*\.[0-9]*\.[0-9]*" --color=never)
+      - export RELEASE_DIRECTORY="/artefacts/deblan/side_menu"
+      - make release
+    when:
+      branch:
+        - master
+
+volumes:
+  - name: artefacts
+    host:
+      path: /var/www/html/_artefacts