Create release.yml, addresses #10

This is a base GitHub Action that builds a number of binaries and adds them to a draft release. I'm not sure if it's correct, which is why I'm putting it in as a PR for review.

.github/workflows/release.yml

@@ -0,0 +1,70 @@
+name: Build Release
+
+on:
+ push:
+ tags:
+ - 'v*'
+
+jobs:
+
+ build-linux:
+ runs-on: ubuntu-latest
+ strategy:
+ matrix:
+ target:
+ - aarch64-unknown-linux-gnu
+ - x86_64-unknown-linux-gnu
+ - x86_64-pc-windows-gnu
+ - x86_64-pc-windows-msvc
+ - aarch64-apple-darwin
+ - x86_64-apple-darwin
+
+ steps:
+ - name: Checkout Passerine
+ - uses: actions/checkout@v2
+ with: 
+ path: passerine
+
+ - name: Checkout Aspen
+ - uses: actions/checkout@v2
+ with: 
+ repository: vrtbl/aspen
+ path: aspen
+
+ - name: Get Toolchain
+ - uses: actions-rs/toolchain@v1
+ with:
+ toolchain: stable
+ target: ${{ matrix.target }}
+ override: true
+
+ - name: Cross-Compile
+ - uses: actions-rs/cargo@v1
+ with:
+ use-cross: true
+ command: build
+ args: --release --manifest-path $GITHUB_WORKSPACE/aspen/Cargo.toml --target=${{ matrix.target }}
+
+ - name: Move Binary
+ - run: mv $GITHUB_WORKSPACE/aspen/target/release/aspen $GITHUB_WORKSPACE/bin/aspen_${{ matrix.target }}
+
+ - name: Create Release
+ id: create_release
+ uses: actions/create-release@v1
+ env:
+ GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+ with:
+ tag_name: ${{ github.ref }}
+ release_name: Release ${{ github.ref }}
+ draft: true
+ prerelease: true
+
+ - name: Upload Release Assets
+ uses: actions/upload-release-asset@v1
+ env:
+ GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+ with:
+ upload_url: ${{ steps.create_release.outputs.upload_url }} 
+ asset_path: $GITHUB_WORKSPACE/bin/aspen_${{ matrix.target }}
+ asset_name: aspen_${{ matrix.target }}
+