Supporting only Linux and macOS builds.

I don't have access to a Windows machine, so I can't fix any bugs that show up in Windows. Also, Windows builds seem to keep passing even though they are actually failing. Not sure why.

Author: ericmjl

.azure-pipelines/azure-pipelines.yml

@@ -4,8 +4,6 @@ jobs:
  matrix:
  py37:
  python.version: "3.7"
- py36:
- python.version: "3.6"
  pool:
  vmImage: macOS-10.14
  steps:
@@ -25,8 +23,6 @@ jobs:
  matrix:
  py37:
  python.version: "3.7"
- py36:
- python.version: "3.6"
  pool:
  vmImage: ubuntu-16.04
  steps:
@@ -52,4 +48,4 @@ jobs:
  displayName: Add conda to PATH
 
  - template: templates/setup-script-win.yml
- - template: templates/nb-docs-win.yml
+ - template: templates/nb-docs-win.yml