[RFC] .js config instead of .json

[StevenLangbroek]

By switching to a .js instead of .json configuration, it would be easier to move all configuration into the actual config file (for example the driver builder and output formatting), and to configure at runtime (based on whatever you like). Think grunt or karma. I imagine this would look something like this:

var mocks = require('./mocks');
var cucumber = require('cucumber-junit');
var fs = require('fs');

module.exports = function(pioneer){
  return pioneer.config({
    format: 'json',
    output: './spec/results/integration.xml',
    before: function(){
      return mocks.start();
    },

    after: function(results){
      fs.writeFileSync(this.output, cucumber(results));
      mocks.stop();
    }
  });
}