Refactoring of aggregated conformal predictor models.
Refactoring of aggregated conformal predictor models.

* AggregatedCp, CrossConformalClassifier and BootstrapConformalClassifier now accept a prototype IcpClassifier or IcpRegressor object as a parameter. They now rely on sklearn.base.clone in order to construct multiple copies of ICP models.
*  CrossConformalClassifier and BootstrapConformalClassifier are now subclasses of AggregatedCp.
* Removed redundant parameter 'x' from get_samples method in BootstrapSampler, CrossSampler and RandomSubSampler.
* Code style changes in order to adhere to PEP8.
* Updated docstrings.

donlnz/nonconformist