`odo.resource(in_memory_object)`

Conceptually, it seems like it should be possible to create an `odo.resource()` from an in-memory object, like a `DataFrame`, for instance. I get an exception when trying to pass a df to `resource()` however. This requires me to persist the dataframe first, and then use `odo.resource()` on the CSV, for example.

Any reason why making a resource out of an in-memory object can't work?

The usecase is exploration, testing, debugging, and fleshing out odo's `resource()` abstraction.

Start by locating odo.resource() and reproducing the exception with an in-memory DataFrame. Read the surrounding resource abstraction and existing handling for CSV inputs before deciding how in-memory objects should fit. Done means the exploration use case works without first persisting the DataFrame, with behavior covered by tests.

Written by the indexing model from the issue text.