drop python 3.6 support

Author: electronstudio

.github/workflows/build.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: macos-11
     strategy:
       matrix:
-        python-version: [ '3.6', '3.7', '3.8', '3.9', '3.10.0-rc.2' ]
+        python-version: [ '3.7', '3.8', '3.9', '3.10.0' ]
     env:
       MACOSX_DEPLOYMENT_TARGET: 10.14
     steps:
@@ -63,7 +63,7 @@ jobs:
       # You can use PyPy versions in python-version.
       # For example, pypy2 and pypy3
       matrix:
-        python-version: [ '3.6', '3.7', '3.8', '3.9', '3.10.0-rc.2', 'pypy-3.6', 'pypy-3.7' ]
+        python-version: [  '3.7', '3.8', '3.9', '3.10.0',  'pypy-3.7' ]
     steps:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
       - uses: actions/checkout@v2
@@ -110,7 +110,7 @@ jobs:
       # You can use PyPy versions in python-version.
       # For example, pypy2 and pypy3
       matrix:
-        python-version:  [ '3.6', '3.7', '3.8', '3.9', '3.10.0-rc.2' ]
+        python-version:  [  '3.7', '3.8', '3.9', '3.10.0' ]
     steps:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
       - uses: actions/checkout@v2