The program cannot be installed

[35609902357]

If I install the program using sudo pip install -U shreddit I get an error saying
praw requires Python '>=3.4' but the running Python is 2.7.16.
python3 version is 3.7.3
python version is 2.7.16
If I install it using sudo pip3 install -U shreddit the installer succeeds, but when I launch it I get this error

shreddit -u user
INFO:shreddit:Logged in as user.
Traceback (most recent call last):
  File "/usr/local/bin/shreddit", line 10, in <module>
    sys.exit(main())
  File "/usr/local/lib/python3.7/dist-packages/shreddit/app.py", line 44, in main
    shredder = Shredder(default_config, args.user)
  File "/usr/local/lib/python3.7/dist-packages/shreddit/shredder.py", line 33, in __init__
    self._recent_cutoff = arrow.now().replace(hours=-self._hours)
  File "/usr/local/lib/python3.7/dist-packages/arrow/arrow.py", line 603, in replace
    raise AttributeError('unknown attribute: "{}"'.format(key))
AttributeError: unknown attribute: "hours"

[EthanZeigler]

See #146