rails g kaminari:views bootstrap4 でprivate method `themes' called for Kaminari::Generators::ViewsGenerator:Class (NoMethodError)というエラーが出る 

# 実行環境
* Windows 10
* Rails 6.0.3.6
* Ruby 3.1.2

# 実践したこと
* gem 'kaminari'を追加し、ページネーションを実装しようとしていました。
* gem導入後、bootstrap用のビューテンプレートを作成しようとし、<br>```rails g kaminari:views bootstrap4```のコマンドを実行したところ、<br>タイトルのようなエラーが発生したため、解決のプロセスをまとめます。
# エラー内容
```言語:ターミナル
% rails g kaminari:views bootstrap4
C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/kaminari-core-1.2.0/lib/generators/kaminari/views_generator.rb:117:in `initialize': Invalid argument @ rb_sysopen - https://api.github.com/repos/amatsuda/kaminari_themes/git/refs/heads/master (Errno::EINVAL)
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/kaminari-core-1.2.0/lib/generators/kaminari/views_generator.rb:117:in `open'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/kaminari-core-1.2.0/lib/generators/kaminari/views_generator.rb:117:in `get_files_in_master'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/kaminari-core-1.2.0/lib/generators/kaminari/views_generator.rb:41:in `themes'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/kaminari-core-1.2.0/lib/generators/kaminari/views_generator.rb:30:in `copy_or_fetch'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/thor-1.2.1/lib/thor/command.rb:27:in `run'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/thor-1.2.1/lib/thor/invocation.rb:127:in `invoke_command'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/thor-1.2.1/lib/thor/invocation.rb:134:in `block in invoke_all'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/thor-1.2.1/lib/thor/invocation.rb:134:in `each'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/thor-1.2.1/lib/thor/invocation.rb:134:in `map'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/thor-1.2.1/lib/thor/invocation.rb:134:in `invoke_all'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/thor-1.2.1/lib/thor/group.rb:232:in `dispatch'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/thor-1.2.1/lib/thor/base.rb:485:in `start'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/railties-6.0.6/lib/rails/generators.rb:276:in `invoke'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/railties-6.0.6/lib/rails/commands/generate/generate_command.rb:26:in `perform'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/thor-1.2.1/lib/thor/command.rb:27:in `run'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/thor-1.2.1/lib/thor/invocation.rb:127:in `invoke_command'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/thor-1.2.1/lib/thor.rb:392:in `dispatch'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/railties-6.0.6/lib/rails/command/base.rb:69:in `perform'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/railties-6.0.6/lib/rails/command.rb:46:in `invoke'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/railties-6.0.6/lib/rails/commands.rb:18:in `<main>'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/bootsnap-1.14.0/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:32:in `require'
        from C:/Ruby31-x64/lib/ruby/gems/3.1.0/gems/bootsnap-1.14.0/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:32:in `require'
        from bin/rails:4:in `<main>'
```

# 解決方法
* [こちら](https://ja.stackoverflow.com/questions/37331/rails-g-kaminariviews-bootstrap3%E3%81%8C%E5%AE%9F%E8%A1%8C%E3%81%A7%E3%81%8D%E3%81%AA%E3%81%84)の記事を参考にし、<br>```$ bundle exec rails g kaminari:views bootstrap4```<br>を実行しbundle経由で実行してあげると、導入することができました。
        
```言語:ターミナル
$ bundle exec rails g kaminari:views bootstrap4
      downloading app/views/kaminari/_first_page.html.haml from kaminari_themes...
   identical  app/views/kaminari/_first_page.html.haml
      downloading app/views/kaminari/_gap.html.haml from kaminari_themes...
   identical  app/views/kaminari/_gap.html.haml
      downloading app/views/kaminari/_last_page.html.haml from kaminari_themes...
   identical  app/views/kaminari/_last_page.html.haml
      downloading app/views/kaminari/_next_page.html.haml from kaminari_themes...
   identical  app/views/kaminari/_next_page.html.haml
      downloading app/views/kaminari/_page.html.haml from kaminari_themes...
   identical  app/views/kaminari/_page.html.haml
      downloading app/views/kaminari/_paginator.html.haml from kaminari_themes...
   identical  app/views/kaminari/_paginator.html.haml
      downloading app/views/kaminari/_prev_page.html.haml from kaminari_themes...
   identical  app/views/kaminari/_prev_page.html.haml
```
同じエラーに遭遇している方の参考になれば幸いです。