input: Write a python function to scrape blog post titles, authors, and excerpts from a given URL using BeautifulSoup.
  assert len(scrape_blog('https://www.exampleblog.com/')['titles']) > 0
  assert len(scrape_blog('https://www.exampleblog.com/')['authors']) > 0
  assert len(scrape_blog('https://www.exampleblog.com/')['texts']) > 0
output: def scrape_blog(url):
      import requests
      from bs4 import BeautifulSoup
      
      response = requests.get(url)
      soup = BeautifulSoup(response.content, 'html.parser')
      
      titles = [title.get_text() for title in soup.find_all('h2', class_='post-title')]
      authors = [author.get_text() for author in soup.find_all('span', class_='post-author')]
      texts = [excerpt.get_text() for excerpt in soup.find_all('div', class_='post-excerpt')]
      
      return {
          'titles': titles,
          'authors': authors,
          'texts': texts
      }