Add http login and password fields #79
Add translation for http login and password #79
Fix composer.json from guzzle/guzzle to guzzle/service
Add login and passwd parameters in MagentoSoapClientParam class #79
Spreads login/pwd for http auth #79

Spreads in
MagentoItemStep attribute / getter /setter
HasValidCredentialsValidator
MagentoSoapClient constructor
spread authenctication in SoapExplorer #79
Fix HasValidCredentialValidators #79