Aict-tools

* Fix modification of input file timestamp in copy runs
* All but the `apply_` scripts should now not modify their input filestamps now

* Fix for apply_cuts: modification date of input file is not modified anymore

* Add support for most sklearn models, before only `sklearn.ensemble` was supported

* Update to sklearn ~0.21.0, use joblib directly (fixes sklearn's DeprecationWarning)
* Improve feature importance plot
* Add citing instructions

* Enable zenodo doi
* Refactored IO, removed the already sparse support for csv completely
* Testing pmml on travis
* Improved log output

Merged PRs:

* ade81cb Merge pull request 78 from fact-project/tables_compability
* b6a41f3 Merge pull request 87 from fact-project/logging
* c087f54 Merge pull request 88 from fact-project/enable_pmml
* f930c2a Merge pull request 89 from fact-project/zenodo

Add optional support for serializing models into the onnx format.