Add release workflow

.github/workflows/release.yml

@@ -0,0 +1,43 @@
+name: Create Release Artifact
+
+on:
+  release:
+    type: [published]
+
+jobs:
+  create-release-artifact:
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Build using Python 3.7
+        uses: actions/setup-python@v2
+        with:
+          python-version: 3.7
+
+      - name: install dependencies [pip]
+        run: |
+          python -m pip install pip --upgrade pip
+          pip install flake8
+          if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+          pip install -e .
+
+      - name: run linter [flake8]
+        run: flake8 .
+
+      - name: run unit tests [pytest]
+        run: pytest
+
+      - name: create build artifact [sdist]
+        run: python setup.py sdist
+
+      - name: get release name
+        id: get_release_name
+        run: echo ::set-out name=VERSION::${GITHUB_REF/refs\/tags\//}
+
+      - name: upload build artifact
+        uses: actions/upload-artifact@v2
+        with:
+          name: limbus-${{ steps.get_release_name.outputs.VERSION }}
+          path: dist/*