Add release workflow

.github/workflows/release.yml

@@ -0,0 +1,78 @@
+name: Release
+
+on:
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+jobs:
+  create-release:
+    runs-on: ubuntu-latest
+    outputs:
+      upload_url: ${{ steps.create-release.outputs.upload_url }}
+    steps:
+      - name: release
+        if: strategy.job-index == 0
+        uses: actions/create-release@v1
+        id: create-release
+        with:
+          draft: false
+          prerelease: false
+          release_name: Release ${{ github.ref }}
+          tag_name: ${{ github.ref }}
+          body: Builds of ktool for Mac, Linux, and Windows
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+  upload-release-assets:
+    needs: create-release
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Set up Python 3.9
+        uses: actions/setup-python@v2
+        with:
+          python-version: 3.9
+
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install pyserial pyinstaller
+
+      - name: Create the executable
+        run: pyinstaller --onefile ktool.py
+
+      - name: Upload the Mac executable
+        if: matrix.os == 'macos-latest'
+        uses: actions/upload-release-asset@v1
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+        with:
+          upload_url: ${{ needs.create-release.outputs.upload_url }}
+          asset_path: dist/ktool
+          asset_name: ktool-mac
+          asset_content_type: application/octet-stream
+
+      - name: Upload the Linux executable
+        if: matrix.os == 'ubuntu-latest'
+        uses: actions/upload-release-asset@v1
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+        with:
+          upload_url: ${{ needs.create-release.outputs.upload_url }}
+          asset_path: dist/ktool
+          asset_name: ktool-linux
+          asset_content_type: application/octet-stream
+
+      - name: Upload the Windows executable
+        if: matrix.os == 'windows-latest'
+        uses: actions/upload-release-asset@v1
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+        with:
+          upload_url: ${{ needs.create-release.outputs.upload_url }}
+          asset_path: dist/ktool.exe
+          asset_name: ktool-win.exe
+          asset_content_type: application/octet-stream