Enable comet.ml and mlflow integration with multiprocessing

comet.ml integration with mlflow works only for single processing. The reason behind this is that comet.ml monkey-patches several packages during import comet_ml. This is probably why the comet_ml import has to be done before all other imports. When a new sub-process is started, the modules are re-imported in the non-patched version, so this is probably why it does not work.