use longText instead of text

Fixes #7

Author: barryvdh

src/migrations/2014_06_03_193005_create_queue_table.php

@@ -18,7 +18,7 @@ public function up()
             $table->integer('status')->default(0);
             $table->integer('retries')->default(0);
             $table->integer('delay')->default(0);
-            $table->text('payload')->nullable();
+            $table->longText('payload')->nullable();
             $table->timestamps();
         });
 	}
@@ -33,4 +33,4 @@ public function down()
         Schema::drop('laq_async_queue');
 	}
 
-}
+}