Add automated tests

[varunsrin]

Need to come up with a set of tests to cover basic functionality. We won't focus on the onmanager, which is a wrapper around the unstable onenote process.

We could instead focus on stubbing out the OneNote process, and testing one-py by creating XML content that represents basic hierarchy and page content, and asserting if we are able to parse the contents into objects correctly.

Some basic content types that should be read correctly are:

Hierarchy

• Notebook
• Section Groups
• Nested Section Groups
• Pages
• Sub-Pages

Page Content

• Title
• Outline
• OE
• InsertedFile
• Ink
• Image