[yt-dev] Issue #617: Load single pf into Rockstar (yt_analysis/yt)

[Sam Skillman]

New issue 617: Load single pf into Rockstar
https://bitbucket.org/yt_analysis/yt/issue/617/load-single-pf-into-rockstar

Sam Skillman:

It would be nice to be able to do:

```
#!python

rh = RockstarHaloFinder(pf)
```

where pf is a single dataset and not a TimeSeriesData.

Responsible: samskillman