remove github tests for Python 3.6

Author: dimitri-yatsenko

.github/workflows/development.yaml

@@ -36,8 +36,6 @@ jobs:
         include:
           - py_ver: "3.7"
             mysql_ver: "5.7"
-          - py_ver: "3.6"
-            mysql_ver: "5.7"
     steps:
       - uses: actions/checkout@v2
       - name: Set up Python ${{matrix.py_ver}}
@@ -106,4 +104,4 @@ jobs:
         with:
           branch: gh-pages
           directory: gh-pages
-          github_token: ${{secrets.GITHUB_TOKEN}}
+          github_token: ${{secrets.GITHUB_TOKEN}}