encode._get_parameters() not setting parameter default

[tovmeod]

When creating the parameter dict it should also get the default value, it should look like this:

parameter = {
'name': field.name,
'required': field.required,
'in': location,
'description': field_description,
'type': field_type or 'string',
'default': field.schema.default,
}

see encode.py:183