Use airspeed velocity for benchmarking
Since `vbench` was (at least in part) an inspiration for [Airspeed Velocity](https://github.com/spacetelescope/asv/) (`asv`), I think getting something like this set up for `pandas` would be useful and extremely helpful for us and for `asv`. We have a _ton_ of `vbench` code and we'd probably be a great project for pushing the boundaries of and finding edge cases in `asv`. This would also be a great for someone to get to know the scale of datasets for which pandas was designed.

Here's a nice demo of `astropy` using `asv`: http://mdboom.github.io/astropy-benchmark
