Rename Step related classes to Serenity prefix
Rename additional items to Serenity
Move Extract class to serenity_bdd package
Move Metafilter to serenity_bdd package while keeping deprecated variation in thucydides package

serenity_bdd annotation takes precedence over thucydides if both are defined
Merge pull request #6 from mikezx6r/final_moves

Final classes moved to serenity_bdd and Serenity prefix names