Set the minimum automatic limit to 2

Fixes #24
Fixes #23

Author: sindresorhus

readme.md

@@ -58,7 +58,7 @@ grunt.registerTask('default', ['concurrent:target1', 'concurrent:target2']);
 ### limit
 
 Type: `Number`  
-Default: Number of CPU cores (`require('os').cpus().length`)
+Default: Number of CPU cores (`require('os').cpus().length`) with a minimum of 2
 
 Limit of how many tasks that are run concurrently.
 

tasks/concurrent.js

@@ -7,7 +7,7 @@ module.exports = function (grunt) {
 		var spawnOptions;
 		var cb = this.async();
 		var options = this.options({
-			limit: require('os').cpus().length
+			limit: Math.max(require('os').cpus().length, 2)
 		});
 		// Set the tasks based on the config format
 		var tasks = this.data.tasks || this.data;