Loosen bundler dependency, fix ci

Author: iloveitaly

.github/workflows/ruby.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: ['1.9', '2.0', '2.1', '2.2', '2.4', 2.5', '2.6', '2.7', '3.0', '3.1']
+        ruby-version: ['1.9', '2.0', '2.1', '2.2', '2.4', '2.5', '2.6', '2.7', '3.0', '3.1']
 
     steps:
     - uses: actions/checkout@v3

hash_diff.gemspec

@@ -18,7 +18,7 @@ Gem::Specification.new do |spec|
   spec.test_files    = spec.files.grep(%r{^(spec|features)/})
   spec.require_paths = ["lib"]
 
-  spec.add_development_dependency "bundler", "~> 2.2"
+  spec.add_development_dependency "bundler"
   spec.add_development_dependency "rake"
   spec.add_development_dependency "rspec", "~> 3.1"
 end