Ububtu 18.04(64 Bit) server new instance

Python version: 3.6.9
pip 20.3 installed
google chrome version 87.0.42680.66
firefox and firefoxdriver installed as well

```
# imports
from instapy import InstaPy
from instapy import smart_run

# login credentials
insta_username = 'username'
insta_password = 'password'

comments = ['Nice shot! @{}',
'I love your profile! @{}',
'Your feed is an inspiration :thumbsup:',
'Just incredible :open_mouth:',
'What camera did you use @{}?',
'Love your posts @{}',
'Looks awesome @{}',
'Getting inspired by you @{}',
':raised_hands: Yes!',
'I can feel your passion @{} :muscle:']

# get an InstaPy session!
# set headless_browser=True to run InstaPy in the background
session = InstaPy(username=insta_username,
password=insta_password,
headless_browser=False)

with smart_run(session):
""" Activity flow """
# general settings
session.set_dont_include(["friend1", "friend2", "friend3"])

# activity
session.like_by_tags(["natgeo"], amount=10)

# Joining Engagement Pods
session.set_do_comment(enabled=True, percentage=35)
session.set_comments(comments)
session.join_pods(topic='sports', engagement_mode='no_comments')
```

python3 quickstart.py
```

InstaPy Version: 0.6.12
._. ._. ._. ._. ._. ._. ._.
Workspace in use: "/root/InstaPy"
Traceback (most recent call last):
File "quickstartnew.py", line 25, in
headless_browser=False)
File "/usr/local/lib/python3.6/dist-packages/instapy/instapy.py", line 335, in __init__
geckodriver_log_level,
File "/usr/local/lib/python3.6/dist-packages/instapy/browser.py", line 136, in set_selenium_local_session
options=firefox_options,
File "/usr/local/lib/python3.6/dist-packages/selenium/webdriver/firefox/webdriver.py", line 174, in __init__
keep_alive=True)
File "/usr/local/lib/python3.6/dist-packages/selenium/webdriver/remote/webdriver.py", line 157, in __init__
self.start_session(capabilities, browser_profile)
File "/usr/local/lib/python3.6/dist-packages/selenium/webdriver/remote/webdriver.py", line 252, in start_session
response = self.execute(Command.NEW_SESSION, parameters)
File "/usr/local/lib/python3.6/dist-packages/selenium/webdriver/remote/webdriver.py", line 321, in execute
self.error_handler.check_response(response)
File "/usr/local/lib/python3.6/dist-packages/selenium/webdriver/remote/errorhandler.py", line 242, in check_response
raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: Process unexpectedly closed with status 1
```

Reproduce the command from quickstartnew.py using the listed Python, Ubuntu, and browser setup, then trace the failure through instapy.py and browser.py into Selenium's Firefox WebDriver. The report does not define a requested change or acceptance criteria, so confirm the intended fix and what successful startup should look like before proceeding.

索引モデルが issue の本文から書いたものです。