Create a rail pipeline for running informer and estimator

[drewoldag]

Currently the informer and estimator stages are run in a jupyter notebook. We should have at least an example RAIL pipeline.

[OliviaLynn]

Note that if we want to base this off a notebook, we can generate the pipeline/pipeline config yaml file pair automatically with a call like pipe.save("pipe_saved.yml") (shown here in the documentation)