Fallback to 3.6 due to unresolved notebook dependencies

Author: juhasch

appveyor.yml

@@ -8,20 +8,20 @@ cache:
   - '%LOCALAPPDATA%\pip\Cache'
 environment:
   matrix:
-    - TOXENV: 'py37-notebook57'
-      TOXPYTHON: C:\Python37-x64\python.exe
-      PYTHON_HOME: C:\Python37-x64
-      PYTHON_VERSION: '3.7'
+    - TOXENV: 'py36-notebook57'
+      TOXPYTHON: C:\Python36-x64\python.exe
+      PYTHON_HOME: C:\Python36-x64
+      PYTHON_VERSION: '3.6'
       PYTHON_ARCH: '64'
-    - TOXENV: 'py37-notebook64'
-      TOXPYTHON: C:\Python37-x64\python.exe
-      PYTHON_HOME: C:\Python37-x64
-      PYTHON_VERSION: '3.7'
+    - TOXENV: 'py36-notebook64'
+      TOXPYTHON: C:\Python36-x64\python.exe
+      PYTHON_HOME: C:\Python36-x64
+      PYTHON_VERSION: '3.6'
       PYTHON_ARCH: '64'
-    - TOXENV: 'py37-notebook'
-      TOXPYTHON: C:\Python37-x64\python.exe
-      PYTHON_HOME: C:\Python37-x64
-      PYTHON_VERSION: '3.7'
+    - TOXENV: 'py36-notebook'
+      TOXPYTHON: C:\Python36-x64\python.exe
+      PYTHON_HOME: C:\Python36-x64
+      PYTHON_VERSION: '3.6'
       PYTHON_ARCH: '64'
 init:
   - ps: echo $env:TOXENV

tox.ini

@@ -6,7 +6,7 @@ envlist =
     clean,
     check,
     lint,
-    py37-notebook{57,64},
+    py36-notebook{57,64},
     report,
 
 [testenv]