add rudimentary ci process (#4)

Signed-off-by: Kent Rancourt <[email protected]>

.github/workflows/ci.yaml

@@ -0,0 +1,34 @@
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches:
+    - main
+
+jobs:
+  test-bot:
+    strategy:
+      matrix:
+        os: [ubuntu-22.04, macos-13, macos-15]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Set up Homebrew
+        id: set-up-homebrew
+        uses: Homebrew/actions/setup-homebrew@master
+
+      - name: Cache Homebrew Bundler RubyGems
+        uses: actions/cache@v4
+        with:
+          path: ${{ steps.set-up-homebrew.outputs.gems-path }}
+          key: ${{ matrix.os }}-rubygems-${{ steps.set-up-homebrew.outputs.gems-hash }}
+          restore-keys: ${{ matrix.os }}-rubygems-
+
+      - run: brew test-bot --only-cleanup-before
+
+      - run: brew test-bot --only-setup
+
+      - run: brew test-bot --only-tap-syntax
+
+      - run: brew test-bot --only-formulae
+        if: github.event_name == 'pull_request'