URLExtract no longer support Python 3.6 because of filelock recent changes

[za]

Hi @lipoja I see this ERROR on my project:

  File "/home/zaki/git/blue/eggs/urlextract-1.5.0-py3.6.egg/urlextract/cachefile.py", line 19, in <module>
    import filelock                                                     
  File "/home/zaki/git/blue/eggs/filelock-3.4.2-py3.6.egg/filelock/__init__.py", line 8
    from __future__ import annotations                                                     
    ^                                                                                       
SyntaxError: future feature annotations is not defined 

I suggest we need to show which Python version we support. Currently filelock is dropping support for Python3.6 https://py-filelock.readthedocs.io/en/latest/changelog.html#v3-4-2-2021-12-16

[vorenhoutgithub]

See #167