add python 3.6 to matrix (#54)

Author: cmeissner

.github/workflows/main.yml

@@ -10,7 +10,7 @@ jobs:
     strategy:
       matrix:
         phpipam-version: ['1.4x', '1.5x']
-        python-version: ['3.7.x', '3.8.x', '3.9.x', '3.10.x']
+        python-version: ['3.6.x', '3.7.x', '3.8.x', '3.9.x', '3.10.x']
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-python@v2