Use new cache false option. Faster streaming

[arj03]

This is a "test" for flumedb/flumelog-offset#10 and dominictarr/pull-cursor#2. On my machine stream goes from around 25k/s to 30k/s.

[dominictarr]

that's good but it should be a separate benchmark (so we can measure the impact of the cache)

[dominictarr]

I mean, separate function in the benchmark.
feel free to merge, though

[arj03]

Right, makes sense. Thanks! Fixed and merged.