fixed newline output after help information (#833)

index.js

@@ -1130,6 +1130,7 @@ Command.prototype.helpInformation = function() {
     .concat(desc)
     .concat(options)
     .concat(cmds)
+    .concat([''])
     .join('\n');
 };
 

test/test.command.helpInformation.js

@@ -0,0 +1,24 @@
+var program = require('../')
+  , sinon = require('sinon').sandbox.create()
+  , should = require('should');
+
+
+program.command('somecommand');
+program.command('anothercommand [options]');
+
+var expectedHelpInformation = [
+  '',
+  '  Usage:  [options] [command]',
+  '',
+  '  Options:',
+  '',
+  '    -h, --help                output usage information',
+  '',
+  '  Commands:',
+  '',
+  '    somecommand',
+  '    anothercommand [options]',
+  '\n'
+].join('\n');
+
+program.helpInformation().should.equal(expectedHelpInformation);