Tiny speedup by removing command.toLowerCase()

This is not necessary as the command itself is only used from inside the code and as they are (now) all lower case it is safe to remove the toLowerCase

test/commands/watch.spec.js

@@ -32,7 +32,7 @@ describe("The 'watch' method", function () {
             });
 
             it('does not execute transaction if watched key was modified prior to execution', function (done) {
-                client.watch(watched);
+                client.WATCH(watched);
                 client.incr(watched);
                 var multi = client.multi();
                 multi.incr(watched);