Use snap actions instead of the broken container

The container didn't work properly for our base snap anyway.

.github/workflows/deploy.yml

@@ -30,25 +30,27 @@ jobs:
         if: ${{ github.event_name == 'release' && github.event.release.prerelease }}
   snap:
     runs-on: ubuntu-latest
-    container: snapcore/snapcraft
     steps:
       - uses: actions/checkout@v2
       - run: |
           VERSION=$(grep '"version"' package.json | cut -d '"' -f 4)
           echo $VERSION
           sed -i "s/@VERSION@/$VERSION/g" snap/snapcraft.yaml
-      - run: snapcraft
+      - uses: snapcore/action-build@v1
+        id: snapcraft
       - uses: actions/upload-artifact@v2
         with:
           name: snap
-          path: novnc*.snap
-      - run: |
-          mkdir .snapcraft
-          echo ${SNAPCRAFT_LOGIN} | base64 --decode --ignore-garbage > .snapcraft/snapcraft.cfg
-        env:
-          SNAPCRAFT_LOGIN: ${{secrets.SNAPCRAFT_LOGIN}}
-        if: ${{ github.event_name == 'release' }}
-      - run: snapcraft push --release=stable *.snap
+          path: ${{ steps.snapcraft.outputs.snap }}
+      - uses: snapcore/action-publish@v1
+        with:
+          store_login: ${{ secrets.SNAPCRAFT_LOGIN }}
+          snap: ${{ steps.build.outputs.snap }}
+          release: stable
         if: ${{ github.event_name == 'release' && !github.event.release.prerelease }}
-      - run: snapcraft push --release=beta *.snap
+      - uses: snapcore/action-publish@v1
+        with:
+          store_login: ${{ secrets.SNAPCRAFT_LOGIN }}
+          snap: ${{ steps.build.outputs.snap }}
+          release: beta
         if: ${{ github.event_name == 'release' && github.event.release.prerelease }}