input: Write a function to create a web scraper in Python that collects all the links from a given website URL. The function should return a list of all the href attributes found in anchor tags.
  assert scrape_links("http://www.example.com/")==["http://www.iana.org/domains/example"]
  assert scrape_links("http://www.google.com/")==["/intl/en/ads/","/services/","/intl/en/about.html","http://www.google.com/"]
  assert scrape_links("http://www.github.com/")==["https://github.com/about","https://github.com/enterprise","https://github.com/explore","https://github.com/marketplace","https://github.com/pricing","https://github.com/login?return_to=%2F"]
  assert scrape_links("")==[]
output: def scrape_links(url):
      import requests
      from bs4 import BeautifulSoup
      if not url:
          return []
      response = requests.get(url)
      soup = BeautifulSoup(response.text, 'html.parser')
      links = [a['href'] for a in soup.find_all('a', href=True)]
      return links