Support complex parameter inputs

🚀 Feature

The current method for injecting parameters into the Jupyter Notebooks requires that the input values be a valid JSON type else they are coerced into their object.__repr__() representation. papermill should support more complex data types via another protocol (pickle maybe?) for a better user experience

Motivation

When calling papermill from the command line, JSON types are adequate because it is difficult for the user to represent anything more complex than that. However when calling papermill programmatically, user defined types and classes are much easier to create and are not supported. Obviously there are workarounds such as writing to a file and reading the values back in on the other end, but it would be better if papermill could support something like this natively.