no editable install on appveyor

editable doesn't resolve setup_requires dependencies with requires_python correctly

Author: minrk

appveyor.yml

@@ -21,7 +21,7 @@ install:
         python -m pip install --upgrade setuptools pip wheel
         pip --version
   - cmd: |
-        pip install --pre -e .
+        pip install --pre .
         pip install ipykernel[test]
   - cmd: |
         pip install matplotlib numpy