Drop support for Python 3.6 (#1004)

* Drop support for Python 3.6
* Remove unused time parsing function
* Use Python 3.7 datetime function for writing stats data conversion
* Test against Python 3.10 on macOS and Windows

.github/workflows/test_linux.yml

@@ -12,7 +12,7 @@ jobs:
   testLinux:
     strategy:
       matrix:
-        python-version: ["3.6", "3.7", "3.8", "3.9", "3.10"]
+        python-version: ["3.7", "3.8", "3.9", "3.10"]
     runs-on: ubuntu-latest
     steps:
       - name: Python Setup

.github/workflows/test_mac.yml

@@ -15,7 +15,7 @@ jobs:
       - name: Python Setup
         uses: actions/setup-python@v2
         with:
-          python-version: 3.9
+          python-version: "3.10"
           architecture: x64
       - name: Install Packages
         run: |

.github/workflows/test_win.yml

@@ -15,7 +15,7 @@ jobs:
       - name: Python Setup
         uses: actions/setup-python@v2
         with:
-          python-version: 3.9
+          python-version: "3.10"
           architecture: x64
       - name: Checkout Source
         uses: actions/checkout@v2