Add GitHub Actions workflow for building packages

.github/workflows/build.yml

@@ -0,0 +1,25 @@
+name: CI
+"on":
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+jobs:
+  Build:
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version: "3.10"
+          cache: "pip"
+          cache-dependency-path: "**/setup.py"
+      - run: pip install build -e .
+      - run: make import-cldr
+      - run: python -m build
+      - uses: actions/upload-artifact@v3
+        with:
+          name: dist
+          path: dist