EducationalTestingService/skll — pull request #219 by mheilman (2014-12-05 15:06:42+00:00)
Title: fix to support int labels

Integer labels get converted to `numpy.int64` objects when the input is read in, and these can't be JSON-serialized. This causes `run_experiment` to fail when trying to write JSON results files---specifically, the descriptive statistics about the training data.

I adapted this solution for a related problem:
http://stackoverflow.com/questions/11561932/why-does-json-dumpslistnp-arange5-fail-while-json-dumpsnp-arange5-tolis

Check out this craziness:
```
ipdb> json.dumps(np.float64(4.0))
'4.0'
ipdb> json.dumps(np.int64(4))
*** TypeError: 4 is not JSON serializable
ipdb>
```