Update gem version to 1.2.1

[masashimorita]

Update gem version
@westonplatter

[masashimorita]

@westonplatter
Would you please check this PR?

[westonplatter]

@masashimorita what changes would be included in this version bump?

[masashimorita]

@westonplatter
It would be the changes which are merged to master since v1.2.0 released.

• Add dupe check passing two fingerprints #50
• Add meta methods: dupe_at_threshold_<n>? #63
• [CI] Test against Ruby 2.4 and 2.5 #73
• Fix readme #70
• feature, ci. create github action ci. #88
• Travis xenial #89
• Fix installation failure for Ruby 3.1 and 3.2 on Mac OS #94
• chore: Add Ruby 3.1 and 3.2 to CI matrix #91

[dvandersluis]

Will this be released anytime soon?

[kimegede]

I would like to see this PR merged as well 🥺 🙏

[westonplatter]

@masashimorita Thank you for pulling together the merged PRs - it makes a difference seeing a concrete list. Thanks.

I'm game to release a version bump.

Given the new method in #50, I'm think a minor release is more appropriate. I'm basing my logic from https://semver.org/#spec-item-7. Thoughts?

Given the this gem is older and updated less, I would rather side with caution and give the large user base ample chance to digest what's changing. I don't want to make a quick decision that negatively impacts downstream users.

[kimegede]

Think minor or patch is acceptable for these changes 🤞