fix h5py version to 3.1; put pip stuff into environment.yml

environment.yml

@@ -2,6 +2,13 @@ name: tutorial-env
 channels:
   - conda-forge
 dependencies:
+  - python
+  - pip
+  - pip:
+    - tensorflow
+    - scikit-learn
+    - torch
+  - h5py<3.2
   - hyperspy-base
   - hyperspy-gui-ipywidgets
   - ipympl