Add dist check worflow

.github/workflows/dist.yml

@@ -0,0 +1,31 @@
+name: dist-check
+
+on: [push, pull_request]
+
+jobs:
+  dist:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Setup Python
+      uses: actions/setup-python@v2
+      with:
+        python-version: 3.8
+    - name: Build dist
+      run: |
+        python setup.py sdist
+    - name: Twine check
+      run: |
+        pip install twine
+        last_dist=$(ls -t dist/autoPyTorch-*.tar.gz | head -n 1)
+        twine_output=`twine check "$last_dist"`
+        if [[ "$twine_output" != "Checking $last_dist: PASSED" ]]; then echo $twine_output && exit 1;fi
+    - name: Install dist
+      run: |
+        last_dist=$(ls -t dist/autoPyTorch-*.tar.gz | head -n 1)
+        pip install $last_dist
+    - name: PEP 561 Compliance
+      run: |
+        pip install mypy
+        cd ..  # required to use the installed version of autosklearn
+        if ! python -c "import autoPyTorch"; then exit 1; fi