Cannot use dabatasedotcom objects with Ruby

I'm new to Ruby and I'm trying to connect my application with SalesForce using the database.com gem. My goal is to develop a gem that wraps the Databasedotcom gem, an than use my own wrapper gem in a rails project.

I've installed the databasedotcom gem with bundler.

My Gemfile has the gem declaration:

gem 'databasedotcom'

I've generated my credentials at salesforce (user + pass) and (client_id and client_secret). I used a curl script to test the connection and I was even able to connect to my account.

config/databasedotcom.yml:

host: login.salesforce.com        # Use test.salesforce.com for sandbox
client_secret: mySecret           # This is the Consumer Secret from Salesforce
client_id: myClientID             # This is the Consumer Key from Salesforce
sobject_module: SFDC_Models       # See below for details on using modules
debugging: true                   # Can be useful while developing
username: myusername
password: mypassword

The problem occurs when I'm trying to use the objects inside my code, for example:

require_relative "test_helper"
class SalesforceclientTest < MiniTest::Test
    def test_send_lead
        client = Databasedotcom::Client.new("databasedotcom.yml")
        client.materialize("User")
        @users = Databasedotcom::User.all()[0..19]
    end
end

When I run rake, it gives me the following error:

NameError: uninitialized constant SalesforceclientTest::Databasedotcom

I've also tried to put:

require databasedotcom

in the beginning of the test code, but than, when I re-run rake, it gives me:

require': cannot load such file -- databasedotcom (LoadError)

It's probably something stupid but I can't figure it out. Any help?

Thanks,