updates for Rails 8.0

[MichaelWhi]

Updates for Rails 8.0

Tests run after updating sqlite gem in Gemfile.lock:

$ bin/test
DEPRECATION WARNING: `to_time` will always preserve the full timezone rather than offset of the receiver in Rails 8.1. To opt in to the new behavior, set `config.active_support.to_time_preserves_timezone = :zone`. (called from <top (required)> at /workspaces/devise-uncommon_password/test/dummy/config/environment.rb:5)
DEPRECATION WARNING: `to_time` will always preserve the full timezone rather than offset of the receiver in Rails 8.1. To opt in to the new behavior, set `config.active_support.to_time_preserves_timezone = :zone`. (called from <top (required)> at /workspaces/devise-uncommon_password/test/dummy/config/environment.rb:5)
Run options: --seed 62839

# Running:

.......

Finished in 1.477656s, 4.7372 runs/s, 139.4100 assertions/s.
7 runs, 206 assertions, 0 failures, 0 errors, 0 skips

I did not change it in the gemspec, so older versions still work.

(@HCLarsen What are your thoughts about (new) automated tests based on Github Workflows instead of Travis? Maybe using https://github.com/makandra/gemika or something similar? If you think it's a good idea, I could add a PR.)

[HCLarsen]

@MichaelWhi I'm not familiar with Github workflows, but Travis cancelled their free options, so this repo has actually been without a CI for a while. I'd be interested to see how that works.