input: Write a function to scrape all links from a webpage using BeautifulSoup.
  assert scrape_links("http://www.example.com/")==['http://www.iana.org/domains/example', 'http://www.example.com']
  assert scrape_links("http://www.testpage.com/")==['http://www.testpage.com/link1', 'http://www.testpage.com/link2']
  assert scrape_links("http://www.anotherpage.com/")==['http://www.anotherpage.com/home', 'http://www.anotherpage.com/about']
output: def scrape_links(url):
      import requests
      from bs4 import BeautifulSoup
  
      response = requests.get(url)
      soup = BeautifulSoup(response.content, 'html.parser')
      links = [a['href'] for a in soup.find_all('a', href=True)]
      return links