Implemented alternate MULTI syntax

Usage:

  client
    .multi
    .set(foo, bar)
    .set(counter, 1)
    .incr(counter)
    .exec(function(err, replies){});

test.js

@@ -339,30 +339,33 @@ tests.MSETNX = function () {
 
 tests.MULTI = function () {
     var name = "MULTI";
-    client.multi([
-        ["mset", ["multifoo", "10", "multibar", "20"], require_string("OK", name)],
-        ["set", ["foo2"], require_error(name)],
-        ["incr", ["multifoo"], require_number(11, name)],
-        ["incr", ["multibar"], require_number(21, name)]
-    ]);
 
-    client.multi([
-        ["incr", ["multibar"], require_number(22, name)],
-        ["incr", ["multifoo"], require_number(12, name)]
-    ]);
-    
-    client.multi([
-        ["mget", ["multifoo", "multibar"], function (err, res) {
-            assert.strictEqual(2, res.length, name);
-            assert.strictEqual("12", res[0].toString(), name);
-            assert.strictEqual("22", res[1].toString(), name);
-        }],
-        ["set", ["foo2"], require_error(name)],
-        ["incr", ["multifoo"], require_number(13, name)],
-        ["incr", ["multibar"], require_number(23, name)]
-    ], function (reply) {
-        next(name);
-    });
+    client
+      .multi
+      .mset('some', '10', 'keys', '20')
+      .incr('some')
+      .incr('keys')
+      .exec(function(err, replies){
+          assert.strictEqual(null, err);
+          assert.equal('OK', replies[0]);
+          assert.equal(11, replies[1]);
+          assert.equal(21, replies[2]);
+          next(name);
+      });
+};
+
+tests.MULTI_ERROR = function () {
+    var name = "MULTI_ERROR";
+
+    client
+      .multi
+      .set('something', 'amazing')
+      .set('invalid')
+      .exec(function(err, replies){
+          assert.equal("ERR wrong number of arguments for 'set' command", err.message);
+          assert.strictEqual(undefined, replies);
+          next(name);
+      });
 };
 
 tests.HGETALL = function () {