Allow to assign a function directly to query.config about nunjucks-loader

[at0g]

It would be nice, but...
The query is a string, and can also be used inline require('nunjucks!tpl.njk?config=...').
It might be possible with eval (provided the supplied value is a string rather than a function), but I can see that approach coming with it's own set of problems.

I may be misunderstanding something here, but I looked at the source and there is this chunk of code

if (query.config) {
  pathToConfigure = query.config;
  try {
    var configure = require(query.config);
    configure(env);
  }
....

So I tought it would be possible to do something like this

if (query.config) {
  pathToConfigure = query.config;
  try {
    var configure   
    if (typeof query.config === 'function')
      configure = query.config;
    else
      configure =  require(query.config);
    configure(env);
  }
....

I've forked this repo and tried to do this myself but, for some reason I really don't undestand, I couldn't get the tests to work in my machine.

[at0g]

@vtfn
What was the problem you had with the tests - maybe I can help you out with that?

Regarding your previous comment:

console.log(typeof query.config === 'string') // always true