ContextPath will missing when run in node

[alasq]

Describe the issue
ContextPath will missing when run in node.
nginx set proxy :80/mock/ to :1080/
So i need add contextPath setting. But in sendEequest.js not support contextPath.

What you are trying to do
Description of what you are trying to do so we can understand the context of the problem

MockServer version
The version you are using (i.e. 5.15.0)