buid with newer poetry and drop 3.6 build

Author: Andrew Dorton

.github/workflows/build.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.6, 3.7, 3.8, 3.9, "3.10"]
+        python-version: [3.7, 3.8, 3.9, "3.10"]
 
     steps:
     - uses: actions/checkout@v2
@@ -26,7 +26,7 @@ jobs:
     - name: Set up Poetry
       uses: abatilo/[email protected]
       with:
-        poetry-version: 1.1.5
+        poetry-version: 1.3.1
     - name: Install dependencies
       run: poetry install
     - name: Run tests