input: Write a python function to read a CSV file and plot a line chart of the closing prices using Plotly.
  assert type(create_plot('AAPL_data.csv')) is go.Figure
output: import plotly.graph_objects as go
  import pandas as pd
  
  def create_plot(file_path):
      df = pd.read_csv(file_path)
      fig = go.Figure()
      fig.add_trace(go.Scatter(x=df['Date'], y=df['Close'], mode='lines', name='Closing Prices'))
      fig.update_layout(title='Closing Prices Over Time', xaxis_title='Date', yaxis_title='Closing Price')
      return fig