fix the workflow to test code

Author: Knerio

.github/workflows/main.yml

@@ -3,7 +3,7 @@ name: Ruby
 on:
   push:
     branches:
-      - master
+      - main
 
   pull_request:
 
@@ -24,4 +24,4 @@ jobs:
         ruby-version: ${{ matrix.ruby }}
         bundler-cache: true
     - name: Run the default task
-      run: bundle exec rake
+      run: bin/rake