Update username length

Author: relliv

src/database/migrations/2014_10_12_000000_create_users_table.php

@@ -18,7 +18,7 @@ public function up()
 
             $table->string('name');
             $table->string('email')->unique();
-            //$table->string('username')->nullable()->unique();
+            // $table->string('username', 50)->nullable()->unique();
             $table->timestamp('email_verified_at')->nullable();
             $table->string('password');
             $table->rememberToken();