Added initial GitHub Actions configuration

.github/workflows/main.yml

@@ -0,0 +1,20 @@
+name: CI
+
+on:
+  push:
+  pull_request:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+
+  tests:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - uses: actions/setup-python@v5
+      with:
+        python-version: '3.12'
+    - run: pip install kaitaistruct