UnicodeEncodeError Exception when type(value) is unicode

On the mfabrik.zoho.cmr._prepare_xml_request method the value is check to see if it's a dict or a str, if not it will do a str conversion. If type(value) is unicode this will result in a UnicodeEncodeError exception, so I changed the check from 'type(value) != str' to 'type(value) not in [str, unicode]' so unicode values can be sent as unicode to Zoho.