input: Write a function to create a web server using the Flask framework that serves a JSON object containing the current temperature for a city based on the city name provided in the request. If the city name is not provided or the request fails, return a JSON object with an error message.
  assert get_temp({'city': 'London'})=={'temperature': 280.15}
  assert get_temp({'city': 'New York'})=={'temperature': 290.15}
  assert get_temp({'city': 'Paris'})=={'temperature': 285.15}
  assert get_temp({'city': ''})=={'error': 'City name not provided'}
  assert get_temp({'city': 'InvalidCity'})=={'error': 'Invalid city name'}
output: from flask import Flask, request, jsonify
  
  app = Flask(__name__)
  
  @app.route('/get_temp', methods=['GET'])
  def get_temp():
      city = request.args.get('city')
      if not city:
          return jsonify({'error': 'City name not provided'})
      temperatures = {
          'London': 280.15,
          'New York': 290.15,
          'Paris': 285.15
      }
      if city in temperatures:
          return jsonify({'temperature': temperatures[city]})
      else:
          return jsonify({'error': 'Invalid city name'})