Tweaks to script

.github/workflows/pylint.yml

@@ -1,6 +1,6 @@
 name: Pylint
 
-on: [push]
+on: [push, pull_request]
 
 jobs:
   build:
@@ -9,14 +9,14 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    - name: Set up Python 3.8
-      uses: actions/setup-python@v1
+    - name: Set up Python 3.9
+      uses: actions/setup-python@v2
       with:
-        python-version: 3.8
+        python-version: 3.9
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
         pip install pylint
     - name: Analysing the code with pylint
       run: |
-        find . -name '*.py' -exec pylint {} \;
+        pylint bookwyrm/ --ignore=migrations