MNT: Require wheels for things that cannot be built on CI

Author: effigies

tox.ini

@@ -34,6 +34,7 @@ CHECK =
 description = Typical pytest invocation with coverage
 install_command =
   python -I -m pip install \
+    --only-binary numpy,scipy,h5py
     --extra-index-url https://pypi.anaconda.org/scientific-python-nightly-wheels/simple \
     {opts} {packages}
 pip_pre =