Fix additional linting violations

For some reason #1175 passed, but CI for #1174 is failing.

Author: stevepolitodesign

lib/suspenders/generators.rb

@@ -65,7 +65,7 @@ def raise_if_database_unsupported
 
         def database_unsupported?
           configuration = File.read(Rails.root.join("config/database.yml"))
-          configuration = YAML.load(configuration, aliases: true)
+          configuration = YAML.safe_load(configuration, aliases: true)
           adapter = configuration["default"]["adapter"]
 
           adapter != "postgresql"