input: Write a python function to create a directory if it doesn't already exist using the os module.
  assert create_directory('testDir') == True
  assert create_directory('testDir') == False
  assert create_directory('anotherDir') == True
output: import os
  
  def create_directory(directory):
      if not os.path.exists(directory):
          os.makedirs(directory)
          return True
      return False