Update python3.6 CI (#96)

* neighbor spelling (assuming we're sticking to American spelling!)

* change to checkoutv4

* change to checkout@v3

* change to pythonv4

* change to ubuntu-20.04

* return to latest ubuntu for 3.7 and 3.8, and separately include 3.6 case

* include pythons up to 3.11

* enclose versions in quotes

* revert spelling changes

.github/workflows/CI.yml

@@ -16,12 +16,15 @@ jobs:
  strategy:
  matrix:
  os: [ubuntu-latest]
- python-version: [3.6, 3.7, 3.8]
+ python-version: ['3.7', '3.8', '3.9', '3.10', '3.11']
+ include:
+ - os: ubuntu-20.04
+ python-version: '3.6'
 
  steps:
- - uses: actions/checkout@v2
+ - uses: actions/checkout@v3
  - name: Set up Python ${{ matrix.python-version }}
- uses: actions/setup-python@v2
+ uses: actions/setup-python@v4
  with:
  python-version: ${{ matrix.python-version }}