Inmemory store cannot clean up localstorage if localstorage is full at the start of the session

[Dahaden]

Carrying on from #20

When creating an instance of localstorage-retry, Store will grab the defaultEngine and use this for the originalEngine which is used to drive the reclaim mechanism

My assumption inside of the last PR was that defaultEngine would always be localstorage. However, engine runs a check and assigns the store to localstorage or inmemory before the module is resolved.

This means, if localstorage is so full that we cant insert a uuid and "test_value", then we will only ever run reclaim against the inmemory engine.