AppVeyor: Build all protocol versions on Linux (#21)

* let's try this

* Update appveyor.yml

appveyor.yml

@@ -15,10 +15,24 @@ for:
   matrix:
     only:
       - image: Ubuntu2004
-  before_build:
-    - mkdir -p bin
   build_script:
-    - make
+    - ps: |
+        $versions = "104", "728"
+
+        foreach ($version in $versions) {
+            Write-Output "Cleaning old output"
+            Invoke-Expression "make clean"
+            if ($LASTEXITCODE -ne "0") {
+                Write-Error "make clean failed for version $version" -ErrorAction Stop
+            }
+            Write-Output "Building version $version"
+            Invoke-Expression "make PROTOCOL_VERSION=$version"
+            if ($LASTEXITCODE -ne "0") {
+                Write-Error "make failed for version $version" -ErrorAction Stop
+            }
+            Rename-Item -Path "bin/fusion" -newName "$version-fusion"
+            Write-Output "Built version $version"
+        }
   artifacts:
     - path: bin
       name: ubuntu20_04-bin-x64