Breaking change: Update project and supported Ruby versions (#41)

## Description

This PR updates the project's development Ruby version to v3.3 and the
gem's minimum supported Ruby version to v3.0. This is a breaking change!

Ruby 2.7 EOL was March 2023 so we should be comfortable dropping
support.

## Commits

- Remove upper constraint on supported Ruby versions
- Set project Ruby version to v3.3.0
- Set StandardRB target Ruby version to v3.0
- Remove Ruby 2.7 from test matrix
- Set minimum supported Ruby version to v3.0
- Update documentation reflecting Ruby version support

Author: jgarber623

.github/workflows/ci.yml

@@ -27,7 +27,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [macos-latest, ubuntu-latest]
-        ruby: ["2.7", "3.0", "3.1", "3.2", "3.3"]
+        ruby: ["3.0", "3.1", "3.2", "3.3"]
     steps:
       - uses: actions/checkout@v4
       - uses: ruby/setup-ruby@v1

.ruby-version

@@ -1 +1 @@
-2.7.8
+3.3.0

.standard.yml

@@ -1,2 +1,3 @@
-format: progress
+format: "progress"
 parallel: true
+ruby_version: "3.0"

CONTRIBUTING.md

@@ -8,9 +8,9 @@ There are a couple ways you can help improve webmention-client-ruby:
 
 ## Getting Started
 
-webmention-client-ruby is developed using Ruby 2.7.8 and is tested against additional Ruby versions using [GitHub Actions](https://github.com/indieweb/webmention-client-ruby/actions).
+webmention-client-ruby is developed using Ruby 3.3.0 and is tested against additional Ruby versions using [GitHub Actions](https://github.com/indieweb/webmention-client-ruby/actions).
 
-Before making changes to webmention-client-ruby, you'll want to install Ruby 2.7.8. Using a Ruby version managment tool like [rbenv](https://github.com/rbenv/rbenv), [chruby](https://github.com/postmodern/chruby), or [rvm](https://github.com/rvm/rvm) is recommended. Once you've installed Ruby 2.7.8 using your method of choice, install the project's gems by running:
+Before making changes to webmention-client-ruby, you'll want to install Ruby 3.3.0. Using a Ruby version managment tool like [rbenv](https://github.com/rbenv/rbenv), [chruby](https://github.com/postmodern/chruby), or [rvm](https://github.com/rvm/rvm) is recommended. Once you've installed Ruby 3.3.0 using your method of choice, install the project's gems by running:
 
 ```sh
 bundle install

README.md

@@ -15,9 +15,9 @@
 
 ## Getting Started
 
-Before installing and using webmention-client-ruby, you'll want to have [Ruby](https://www.ruby-lang.org) 2.7 (or newer) installed. Using a Ruby version managment tool like [rbenv](https://github.com/rbenv/rbenv), [chruby](https://github.com/postmodern/chruby), or [rvm](https://github.com/rvm/rvm) is recommended.
+Before installing and using webmention-client-ruby, you'll want to have [Ruby](https://www.ruby-lang.org) 3.0 (or newer) installed. Using a Ruby version managment tool like [rbenv](https://github.com/rbenv/rbenv), [chruby](https://github.com/postmodern/chruby), or [rvm](https://github.com/rvm/rvm) is recommended.
 
-webmention-client-ruby is developed using Ruby 2.7.8 and is tested against additional Ruby versions using [GitHub Actions](https://github.com/indieweb/webmention-client-ruby/actions).
+webmention-client-ruby is developed using Ruby 3.0.0 and is tested against additional Ruby versions using [GitHub Actions](https://github.com/indieweb/webmention-client-ruby/actions).
 
 ## Installation
 

webmention.gemspec

@@ -3,7 +3,7 @@
 require_relative "lib/webmention/version"
 
 Gem::Specification.new do |spec|
-  spec.required_ruby_version = ">= 2.7", "< 4"
+  spec.required_ruby_version = ">= 3.0"
 
   spec.name = "webmention"
   spec.version = Webmention::VERSION