add two benchmark test with new data file (#155)
add two benchmark test with new data file (#155)

The second benchmark test is a for low level column reader call on the new data file. This is theoretically the lower bound of read time needed. We also should aim for this when we implement `Column` and `Table`. Now we can see huge potential for the current implementation:

```
test record_reader_10k_collect   ... bench:  17,203,101 ns/iter (+/- 109,298) = 38 MB/s
test record_reader_stock_collect ... bench: 116,401,996 ns/iter (+/- 1,467,345) = 11 MB/s
test record_reader_stock_column  ... bench:   6,892,490 ns/iter (+/- 26,985) = 187 MB/s
```

* add two benchmark test with new data file

* fix some bad naming and formatting

* change batch size back to 256

* more formatting

* more formattingx2

sunchao/parquet-rs,sunchao/parquet-rs