Run tests nightly

Author: tf

.github/workflows/tests.yml

@@ -1,5 +1,9 @@
 name: tests
-on: [push, pull_request]
+on:
+  push:
+  pull_request:
+  schedule:
+    - cron: '45 2 * * *'
 
 jobs:
   rspec:
@@ -31,4 +35,4 @@ jobs:
           ruby-version: ${{ matrix.ruby-version }}
           bundler-cache: true
       - name: Run tests
-        run: bundle exec rspec
+        run: bundle exec rspec