update git versions

Author: tsolakoua

.github/workflows/build.yml

@@ -12,7 +12,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [3.4, 3.5, 3.6]
+        python-version: [3.4, 3.5, 3.6.8]
 
     steps:
       - uses: actions/checkout@v2

tox.ini

@@ -19,7 +19,7 @@ usedevelop=True
 python =
     3.4: py34
     3.5: py35
-    3.6: py36
+    3.6.8: py36
 
 [flake8]
 max-complexity = 5