title: Flask URL not found when using blueprint
body: <p>This is really strange but am facing this problem. Everything was working and i was almost done with the app but out of a sudden it stopped. I have isolated the code and i realized that when i register a blueprint and use it on a route, it fails to return saying no URL found. Here is the isolated code:</p>
  
  <pre><code>from flask import Flask, render_template, Blueprint
  
  app = Flask(__name__)
  
  home = Blueprint('home', __name__, static_folder='static', template_folder='template')
  app.register_blueprint(home)
  
  
  @home.route('/')  #&lt;---This one does not work
  # @app.route('/') &lt;--- This one works
  def index():
      return "This is the index route."
      # return render_template('layer.html')
  
  
  if __name__ == '__main__':
      app.run()
  </code></pre>