Add tmp fix for manifest name installs

Author: michael-misshore

lib/critical_path_css/rails/config_loader.rb

@@ -22,9 +22,12 @@ def format_css_paths
         if config['css_path']
           config['css_path']  = format_path(config['css_path'])
           config['css_paths'] = []
-        else
+        elsif config['css_paths']
           config['css_path']  = ''
           config['css_paths'] = config['css_paths'].collect { |path| format_path(path) }
+        else
+          config['css_path']  = ActionController::Base.helpers.stylesheet_path(config['manifest_name'], host: '')
+          config['css_paths'] = []
         end
       end
 

spec/lib/critical_path_css/rails/config_loader_spec.rb

@@ -81,7 +81,7 @@
       }
 
       it 'sets css_path with the path' do
-        expect(subject.config['css_path']).to eq '/app/spec/internal/public/test.css'
+        expect(subject.config['css_path']).to eq '/stylesheets/application.css'
       end
 
       it 'leaves css_paths empty' do