curb HTTP client does not work with Traffic Client

[lhagemann]

The HTTP client defined in dyn/http/curb does not properly pass in the the login credentials

The following sample shows the problem, (error output below)

require './lib/dyn-rb.rb'
require './lib/dyn/http/curb.rb'

require 'securerandom'

Dyn::HttpClient.const_set('DefaultClient',Class.new(Dyn::HttpClient::CurbClient))

## Set variables 
DYN_CUST = ENV['DYN_CUST'] || 'customer'
DYN_USER = ENV['DYN_USER'] || 'user'
DYN_PASS = ENV['DYN_PASS'] || 'secretword'
DYN_ZONE = ENV['DYN_ZONE'] || 'example.com'

dyn = Dyn::Traffic::Client.new(DYN_CUST, DYN_USER, DYN_PASS)

Error output:

dyn-rb/lib/dyn/traffic.rb:230:in `parse_response': Request failed: 
ERROR MISSING_DATA API-A - user_name: required field missing (Dyn::Exceptions::RequestFailed)
ERROR MISSING_DATA API-A - customer_name: required field missing
ERROR MISSING_DATA API-A - password: required field missing
    from dyn-rb/lib/dyn/traffic.rb:207:in `api_request'
    from dyn-rb/lib/dyn/traffic.rb:184:in `post'
    from dyn-rb/lib/dyn/traffic/session.rb:29:in `create'
    from dyn-rb/lib/dyn/traffic.rb:71:in `login'
    from dyn-rb/lib/dyn/traffic.rb:62:in `initialize'
    from dyn-rb/sample.rb:16:in `new'
    from dyn-rb/sample.rb:16:in `<main>'