Context.fail does not support custom status codes

[kturcios]

Expected Behaviour

The following code snippet should return a 501 status code along with the error message.

module.exports = (event, context) => {
    context
        .status(501)
        .fail('An error occurred');
}

Current Behaviour

The snippet is returning the default 500 status code along with the error message.

Possible Solution

Modify the fail method inside index.js to use this.value

fail(value) {
        let message;
        this.cb(this.value, message);
}

Steps to Reproduce (for bugs)

Create a handler that returns the following

module.exports = (event, context) => {
    context
        .status(501)
        .fail('An error occurred');
}

Context

I am trying to create a stateless microservice that returns proper status codes.

Your Environment

faas-cli version: 0.8.3
docker version: 18.09.1
OS: MacOS

[alexellis]

Please can you move this to the node10-express repo?