Add workflow to build requirements.

Author: tillahoffmann

.github/workflows/requirements.yml

@@ -0,0 +1,30 @@
+name: testcontainers requirements
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+jobs:
+  requirements:
+    strategy:
+      matrix:
+        python-version:
+          - "3.7"
+          - "3.8"
+          - "3.9"
+          - "3.10"
+          - "3.11"
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Setup python ${{ matrix.python-version }}
+        uses: actions/setup-python@v4
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Update pip and install pip-tools
+        run: pip install --upgrade pip pip-tools
+      - name: Build requirements
+        run: |
+          rm requirements/${{ matrix.python-version }}.txt
+          pip-compile --resolver=backtracking -v --upgrade -o requirements/${{ matrix.python-version }}.txt