BUG: Don't use nonexistent __version__ field.

Author: Scott Sanderson

.github/workflows/release.yml

@@ -31,7 +31,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install --extra-index-url https://test.pypi.org/simple python-interface
-        python -c 'import interface; print(interface.__version__)'
+        python -c 'import interface'
         pip uninstall -y interface
 
     - name: Publish distribution to PyPI
@@ -42,5 +42,7 @@ jobs:
 
     - name: Install and test running
       run: |
+        python -m pip install --upgrade pip
         pip install python-interface
-        python -c 'import interface; print(interface.__version__)'
+        python -c 'import interface'
+        pip uninstall -y interface