Add funding_uri to gemspec

Author: rmm5t

minitest-matchers_vaccine.gemspec

@@ -4,19 +4,27 @@ $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 require 'minitest/matchers_vaccine/version'
 
 Gem::Specification.new do |spec|
+  username           = "rmm5t"
   spec.name          = "minitest-matchers_vaccine"
   spec.version       = Minitest::MatchersVaccine::VERSION
   spec.authors       = ["Ryan McGeary"]
   spec.email         = ["ryan@mcgeary.org"]
   spec.summary       = %q{Adds support for RSpec-style matchers to minitest.}
   spec.description   = %q{Adds matcher support to minitest without all the other RSpec-style expectation "infections."}
-  spec.homepage      = "https://github.com/rmm5t/minitest-matchers_vaccine"
+  spec.homepage      = "https://github.com/#{username}/#{spec.name}"
   spec.license       = "MIT"
 
   spec.files         = Dir["{lib,test}/**/*", "README*", "LICENSE*"]
   spec.test_files    = Dir["{test}/**/*"]
   spec.require_paths = ["lib"]
 
+  spec.metadata = {
+    "bug_tracker_uri"   => "#{spec.homepage}/issues",
+    "changelog_uri"     => "#{spec.homepage}/blob/master/CHANGELOG.md",
+    "source_code_uri"   => spec.homepage,
+    "funding_uri"       => "https://github.com/sponsors/#{username}",
+  }
+
   spec.required_ruby_version = ">= 1.9"
 
   spec.add_dependency "minitest", "~> 5.0"