私の環境はUbuntu18.10、python2.7です。私はSocial_mapperを使いたいのですが、私はpythonを試しました。 しかし、エラーが表示されました。

pwd
/home/ubuntu/san/social_mapper

python social_mapper.py -f imagefolder -i /home/ubuntu/san/social_mapper/image -m fast -a
/home/ubuntu/.local/lib/python2.7/site-packages/bs4/element.py:16: UserWarning: The soupsieve package is not installed. CSS selectors cannot be used.
  'The soupsieve package is not installed. CSS selectors cannot be used.'
[-] Error Filling out Facebook Profiles [-]
Message: 'geckodriver' executable needs to be in PATH. 

[-]
Traceback (most recent call last):
  File "social_mapper.py", line 1112, in <module>
    peoplelist = fill_twitter(peoplelist)
  File "social_mapper.py", line 218, in fill_twitter
    TwitterfinderObject = twitterfinder.Twitterfinder(showbrowser)
  File "/home/ubuntu/san/social_mapper/modules/twitterfinder.py", line 19, in __init__
    self.driver = webdriver.Firefox()
  File "/home/ubuntu/.local/lib/python2.7/site-packages/selenium/webdriver/firefox/webdriver.py", line 164, in __init__
    self.service.start()
  File "/home/ubuntu/.local/lib/python2.7/site-packages/selenium/webdriver/common/service.py", line 83, in start
    os.path.basename(self.path), self.start_error_message)
selenium.common.exceptions.WebDriverException: Message: 'geckodriver' executable needs to be in PATH.