Deploy built images using rsync.

.github/workflows/build.yml

@@ -8,6 +8,7 @@ defaults:
 
 jobs:
   build:
+    environment: Deploy
     runs-on: ${{matrix.os}}
     strategy:
       matrix:
@@ -22,3 +23,9 @@ jobs:
         run: sh -ex build/dependencies.sh install_linux
       - name: Build
         run: make check-dirs all EMULATOR=${{matrix.emulator}}
+      - name: Deploy
+        if: github.ref == 'refs/heads/master'
+        env:
+          SECRET: ${{secrets.SECRET}}
+          EMULATOR: ${{matrix.emulator}}
+        run: sh build/deploy.sh