input: Write a python function to get the stock price from Yahoo Finance.
  assert get_stock_price('AAPL') == 'Expected AAPL price'
  assert get_stock_price('MSFT') == 'Expected MSFT price'
  assert get_stock_price('GOOG') == 'Expected GOOG price'
output: import yfinance as yf
  
  def get_stock_price(ticker):
      stock = yf.Ticker(ticker)
      price = stock.history(period="1d")['Close'].iloc[0]
      return round(price, 2)