Include .jb file by default

[pocke]

jb gem uses .jb extension.
https://github.com/amatsuda/jb

For example: ( https://github.com/amatsuda/jb#examples )

 # app/views/messages/show.json.jb

json = {
  content: format_content(@message.content),
  created_at: @message.created_at,
  updated_at: @message.updated_at,
  author: {
    name: @message.creator.name.familiar,
    email_address: @message.creator.email_address_with_name,
    url: url_for(@message.creator, format: :json)
  }
}

if current_user.admin?
  json[:visitors] = calculate_visitors(@message)
end

json[:comments] = @message.comments.map do |comment|
  {
    content: comment.content,
    created_at: comment.created_at
  }
end

json[:attachments] = @message.attachments.map do |attachment|
  {
    filename: attachment.filename,
    url: url_for(attachment)
  }
end

json

---

Before submitting the PR make sure the following are checked:

• Wrote good commit messages.
• Commit message starts with [Fix #issue-number] (if the related issue exists).
• Used the same coding conventions as the rest of the project.
• Feature branch is up-to-date with master (if not - rebase it).
• Squashed related commits together.
• Added tests.
• Added an entry to the Changelog if the new code introduces user-observable changes. See changelog entry format.
• All tests are passing.
• The new code doesn't generate RuboCop offenses.
• The PR relates to only one subject with a clear title
  and description in grammatically correct, complete sentences.
• Updated cop documentation with rake generate_cops_documentation (required only when you've added a new cop or changed the configuration/documentation of an existing cop).

[koic]

It seems good to '**/*.jb' is above'**/*.jbuilder'.

 ['**/*.jbuilder', '**/*.jb'].sort # => ["**/*.jb", "**/*.jbuilder"]

[pocke]

@koic Thanks! I've sorted it.

[bbatsov]

Guess this should be added to the code that determines if something's Ruby or not as well.

[pocke]

I've added .jb to TargetFinder.