Rename to Serenity

[nyxxxie]

I was on the train today and thought that'd make a much better name than spade. This issue will involve changing the repository name, url, and anything internal that relies in the name "spade". If you're looking at this and interested in following the project, be aware this change will take place in the next few weeks after posting this.

[nyxxxie]

Renamed the repository now since I need the new link now and I expect the period in which it's not current to be small and harmless.