Adding a function to update existing episodes in Channel model.
Adding an option to 'scrape' to update existing episodes instead of skipping them.
Cleaning up scrapeSpec, the loading of test data and the test data itself.

Making the test data for the unit-ish tests less complicated to be easier to understand. Also removing the use of promises that was in use for exactly one call in the entire application for no reason, if required it can be added back in for everything later.
Adding test case for #scrapeSource when updated option is set, and cleaning up scrape test code.
Refactoring scraper to allow options to be passed to different libraries.
Adding path.resolve to a filename being passed that did not have call to resolve.
Adding a test for actually updating and saving in the database using Channel#updateEpisode.

Pretty heavy for a unit test but the prior tests never tried to use save(), which might have caught an issue while developing.
Merge pull request #2 from williamge/scraper-flush

Scraper flush
An unfortunately large commit to change the schema for Episodes and Channels to not be embedded.

Turns out the first thing I wanted to do after saving Channel objects containing embedded Episodes was to use Episode objects on their own, without the Channel.

This commit should also include changes to the tests to make them better tests and to make it more readable.