Improving IDE/notebook experience

[nkanazawa1989]

With #116 we can automatically generate sufficient html for the class documentation, however, the experiment method signature of option setters, e.g. set_experiment_options, is still set_something_options(**fields). This requires the end users to read the code or search for the API docs. This often hurts user experience.

We need to find a way to dynamically override method signature. Perhaps we can use signature object?
https://www.python.org/dev/peps/pep-0362/#signature-object