Add minimal release automation to CI (rust-lang#1129)

Author: tedinski

.github/workflows/release.yml

@@ -0,0 +1,78 @@
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0 OR MIT
+name: Release
+on:
+  push:
+    tags:
+      - kani-*
+
+jobs:
+  Release:
+    name: Release
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Get version
+        run: |
+          # pkgid is something like file:///home/ubuntu/kani#kani-verifier:0.1.0
+          echo "CRATE_VERSION=$(cargo pkgid | cut -d: -f3)" >> $GITHUB_ENV
+          # GITHUB_REF is refs/tags/kani-0.1.0
+          echo "TAG_VERSION=$(echo ${{ github.ref }} | cut -d "-" -f 2)" >> $GITHUB_ENV
+          # Output for upload scripts to see
+          echo ::set-output name=version::$TAG_VERSION
+      - name: Version Check
+        run: |
+          if [[ ${{ env.CRATE_VERSION }} != ${{ env.TAG_VERSION }} ]]; then
+            echo "Git tag ${{env.TAG_VERSION}} did not match crate version ${{env.CRATE_VERSION}}"
+            exit 1
+          fi
+
+      - name: Create release
+        uses: actions/create-release@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          tag_name: kani-${{ env.TAG_VERSION }}
+          release_name: kani-${{ env.TAG_VERSION }}
+          body: |
+            Kani Rust verifier release bundle version ${{ env.TAG_VERSION }}.
+          draft: true
+          prerelease: false
+
+  Upload:
+    name: Upload
+    needs: Release
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [macos-10.15, ubuntu-20.04]
+        include:
+          - os: macos-10.15
+            target: x86_64-apple-darwin
+          - os: ubuntu-20.04
+            target: x86_64-unknown-linux-gnu
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Setup Kani Dependencies
+        uses: ./.github/actions/setup
+        with:
+            os: ${{ matrix.os }}
+      
+      - name: Build release bundle
+        run: |
+          cargo run -p make-kani-release -- ${{ needs.Release.outputs.version }}
+
+      - name: Upload artifact
+        uses: actions/upload-release-asset@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          upload_url: ${{ needs.Release.outputs.upload_url }}
+          asset_path: kani-${{ needs.Release.outputs.version }}-${{ matrix.target }}.tar.gz
+          asset_name: kani-${{ needs.Release.outputs.version }}-${{ matrix.target }}.tar.gz
+          asset_content_type: application/gzip
+