Create build+test.yml

Added a build + test GitHub action for platforms macOS and ubuntu linux

.github/workflows/build+test.yml

@@ -0,0 +1,31 @@
+name: Build & Test (macos & linux)
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build-macos:
+
+    runs-on: macos-latest
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Build
+      run: swift build -v
+    - name: Run tests
+      run: swift test -v
+
+  build-linux:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v3
+    - uses: swift-actions/setup-swift@v1
+    - name: Build
+      run: swift build -v
+    - name: Run tests
+      run: swift test -c release -Xswiftc -enable-testing