butane example

To use this example, build the entire project using cargo build in the project root, and then run these commands in this directory:

1. Initialise a Sqlite database using cargo run -p butane_cli init sqlite db.sqlite
2. Initialise the migrations using cargo run -p butane_cli makemigration initial
3. Migrate the new sqlite database using cargo run -p butane_cli migrate
4. Run the example ../target/debug/example

Any use of cargo to build/run this project will likely delete & recreate the example/.butane directory, and the above steps will need to be repeated.