Resolved rubocop offenses
Resolved rubocop offenses

```
Offenses:

lib/rubicure/core.rb:38:161: C: Metrics/LineLength: Line is too long. [171/160]
    #   #=> {:series_name=>"go_princess", :title=>"Go!プリンセスプリキュア", :started_date=>Sun, 01 Feb 2015, :girls=>["cure_flora", "cure_mermaid", "cure_twinkle", "cure_scarlet"]}
                                                                                                                                                                ^^^^^^^^^^^

25 files inspected, 1 offense detected
```

sue445/rubicure