uninitialized constant Trello (NameError) even though require 'trello'

[kingomarnajjar]

require 'trello'

Trello.configure do |config|
    config.developer_public_key = "253fa2bceab691b4bd18e2ff84******" # The "key" from step 1
    config.member_token = "f9a8132f29fe2ae5cbe65ffde0fecb00437d06de417178de7ff06533fe******" # The token from step 2.
end

bob = Trello::Member.find("omartechlead")

# Print out his name
puts bob.full_name # "Bob Tester"

[hoppergee]

I can't reproduce it. It seems works fine.