Add jupyter notebook example for sqlite

[shravankshenoy]

Fixes #217

Created a jupyter notebook which gives a walkthrough of how to setup and use sql-eval with sqlite database. The major steps involved are as follows:

1. Setting up the defog-data repo
2. Setting up the sql-eval repo
3. Creating and populating the sqlite databases using the translate_ddl_dialect.py script
4. Running the evaluation code (and modifying the question set if required)

I have not run any of the linting or tests since this is a Jupyter notebook, but let me know if I should create or run any. Also let me know if any other changes required.