add optional partnerId param support for connection's getTokenQuery method
add optional partnerId param support for connection's getTokenQuery method

Marketo has an optional partner_id param that you can pass when requesting an oath token
see http://developers.marketo.com/support/Marketo_LaunchPoint_Technology_Partner_API_Key.pdf
usermindinc/node-marketo,MadKudu/node-marketo,MadKudu/node-marketo,usermindinc/node-marketo