Run CI on 3.9

.github/workflows/ci.yml

@@ -20,7 +20,7 @@ jobs:
     strategy:
       matrix:
         os: [ ubuntu-18.04, ubuntu-20.04, macos-latest ]
-        python-version: [3.7, 3.8]
+        python-version: [3.7, 3.8, 3.9]
 
     steps:
     - uses: actions/checkout@v2
@@ -119,7 +119,7 @@ jobs:
     strategy:
       matrix:
         os: [ windows-latest ]
-        python-version: [3.7, 3.8]
+        python-version: [3.7, 3.8, 3.9]
 
     steps:
     - uses: actions/checkout@v2

setup.sh

@@ -42,7 +42,7 @@ function check_installed_python() {
    fi
 
    if [ -z ${PYTHON} ]; then
-        echo "No usable python found. Please make sure to have python3.6 or python3.7 installed"
+        echo "No usable python found. Please make sure to have python3.6, python3.7 or python3.8 installed"
         exit 1
    fi
 }