F001 add author biographies

[scasagrande]

This PR adds backend support for author biographies.

Work is grouped in two commits: One for migrating the DB to include the new fields, and one for adding the new rake command.

DB

• biography and github_issue_id columns added to Authors table
• biography data is added to author_serializer.rb, and was manually checked with curl to verify that the data is returned
• schema updated

Data sync

• New rake command bin/rake github:sync has been added to update author data in the application's database as per story requirements
• Two dependencies have been added to facilitate this rake task (octokit to connect to github API, and literate_randomizer to generate random book titles)
• Author model updated such that destroying an author from the DB will also destroy books foreign key dependencies
• rakefile set to look here for author data: https://github.com/scasagrande/bookstore-authors/issues

Some of my thoughts have been posted as comments in-line.

Readme updates to come, and a few modification to the tests to support this are available, but require PR #1 to be merged first.

[undergroundwebdesigns]

Great first pass, I left a few comments and suggestions for changes I'd like to see, mostly answering your questions and looking for some better error handling.

[undergroundwebdesigns]

Requested a couple more changes, most notably around using transactions to better ensure data consistency.

[undergroundwebdesigns]

Looks good! Go ahead and merge this, and that finishes up the API side of this project.

[scasagrande]

🚢 🚢