Add version number to zip in build workflow

Relay in `github.ref` (the release tag).

.github/workflows/build.yml

@@ -14,13 +14,13 @@ jobs:
           - os: ubuntu-16.04
             # use old linux so that the shared library versioning is more portable
             artifact_name: capa
-            asset_name: capa-linux
+            asset_name: linux
           - os: windows-latest
             artifact_name: capa.exe
-            asset_name: capa-windows
+            asset_name: windows
           - os: macos-latest
             artifact_name: capa
-            asset_name: capa-macos
+            asset_name: macos
     steps:
       - name: Checkout capa
         uses: actions/checkout@v2
@@ -51,11 +51,11 @@ jobs:
     strategy:
       matrix:
         include:
-          - asset_name: capa-linux
+          - asset_name: linux
             artifact_name: capa
-          - asset_name: capa-windows
+          - asset_name: windows
             artifact_name: capa.exe
-          - asset_name: capa-macos
+          - asset_name: macos
             artifact_name: capa
     steps:
       - name: Download ${{ matrix.asset_name }}
@@ -64,12 +64,14 @@ jobs:
           name: ${{ matrix.asset_name }}
       - name: Set executable flag
         run: chmod +x ${{ matrix.artifact_name }}
-      - name: Zip ${{ matrix.artifact_name }} into ${{ matrix.asset_name }}.zip
-        run: zip ${{ matrix.asset_name }}.zip ${{ matrix.artifact_name }}
-      - name: Upload ${{ matrix.asset_name }}.zip to GH Release
+      - name: Set zip name
+        run: echo ::set-env name=zip_name::capa-${GITHUB_REF#refs/tags/}-${{ matrix.asset_name }}.zip
+      - name: Zip ${{ matrix.artifact_name }} into ${{ env.zip_name }}
+        run: zip ${{ env.zip_name }} ${{ matrix.artifact_name }}
+      - name: Upload ${{ env.zip_name }} to GH Release
         uses: svenstaro/upload-release-action@v2
         with:
           repo_token: ${{ secrets.GITHUB_TOKEN}}
-          file: ${{ matrix.asset_name }}.zip
+          file: ${{ env.zip_name }}
           tag: ${{ github.ref }}