Loads a processor

@private
@param {String} processorName
@returns {Function} processor
function _loadProcessor(processorName) {
	const compatibleVersion = compatibleProcessors[processorName]

	// Check if module is compatible
	if(compatibleVersion === undefined) {
		const error = new Error(`Processor ${processorName} is not supported yet.`)
		error.code = 'MODULE_NOT_SUPPORTED'
		throw error
	}

	return require(`./processors/${processorName}`)(_loadModule(processorName))
}