build: update to latest Python 3.9 (#367)

Author: sloria

.github/workflows/test.yml

@@ -8,7 +8,7 @@ jobs:
     - name: Set up Python
       uses: actions/setup-python@v2
       with:
-        python-version: 3.9.0
+        python-version: 3.9
     - name: Install dependencies
       run: ./script/bootstrap
     - name: Run migrations

runtime.txt

@@ -1 +1 @@
-python-3.9.0
+python-3.9.9

script/bootstrap

@@ -5,7 +5,7 @@ set -eu
 if [ -z "${CI:-}" ]; then
   name=${PWD##*/}
   # If python version is passed as first argument, use that, otherwise use 3.9
-  python_version=${1:-3.9.0}
+  python_version=${1:-3.9.9}
   echo "==> Bootstrapping a Python $python_version environment called $name..."
   eval "$(pyenv init -)"
   if ! [ -d "${PYENV_ROOT:-$HOME/.pyenv}/versions/$name" ]; then