GET on default bucket increases quota usage

[glasserc]

While investigating #1225, I discovered that every GET request to e.g. /buckets/default/collections/some-collection causes quota usage to increase. For example,

select * from records where collection_id='quota';
       id        |                                    parent_id                 
                   | collection_id |       last_modified        |               
                data                                
-----------------+--------------------------------------------------------------
-------------------+---------------+----------------------------+---------------
----------------------------------------------------
 bucket_info     | /buckets/74f86a68-a03c-a5f5-fb29-e421b362f5b5                
                   | quota         | 2017-05-22 18:07:14.715782 | {"record_count
": 0, "storage_size": 1745, "collection_count": 13}
 collection_info | /buckets/74f86a68-a03c-a5f5-fb29-e421b362f5b5/collections/a-n
ewest-collection-3 | quota         | 2017-05-22 18:07:14.716923 | {"record_count
": 0, "storage_size": 540}

> http --auth 'user:pass6' 'localhost:8888/v1/buckets/default/collections/a-newest-collection-3'
HTTP/1.1 200 OK
..... more junk .....

select * from records where collection_id='quota';
       id        |                                    parent_id                 
                   | collection_id |       last_modified        |               
                data                                
-----------------+--------------------------------------------------------------
-------------------+---------------+----------------------------+---------------
----------------------------------------------------
 bucket_info     | /buckets/74f86a68-a03c-a5f5-fb29-e421b362f5b5                
                   | quota         | 2017-05-22 18:56:52.448115 | {"record_count
": 0, "storage_size": 1880, "collection_count": 14}
 collection_info | /buckets/74f86a68-a03c-a5f5-fb29-e421b362f5b5/collections/a-n
ewest-collection-3 | quota         | 2017-05-22 18:56:52.4493   | {"record_count
": 0, "storage_size": 600}

This appears to be partly because every request that goes to the default bucket "creates" a bucket and collection.