pydata/pandas — pull request #3103 by jreback (2013-03-20 12:36:42+00:00)
Title: TST: added ensure_clean file cleanup context manager for file based test

avoids leaving temp files around if they are interrupted (during dev),
passes thru exceptions

idiom is:

```
with ensure_clean(path=None) as path:
.....
```

rather than

```
try:
....
finally:
os.remove(path)
```