pin bokeh in the docs/environment.yml file

Author: basnijholt

docs/environment.yml

@@ -4,16 +4,13 @@ channels:
 - conda-forge
 
 dependencies:
-  - python=3.6
+  - python=3.7
   - pip:
     - sortedcollections
     - scipy
-    - holoviews==1.11
-    - bokeh
+    - holoviews==1.12*
+    - bokeh==1.1*
     - plotly
-    - ipyparallel
-    - pandas  # until https://github.com/ioam/holoviews/issues/3430 is fixed
-    - distributed
     - ipywidgets
     - scikit-optimize
     - git+https://github.com/basnijholt/jupyter-sphinx.git@widgets_execute