Added Travis CI config file.
Minor edits to gemspec - added History.md, corrected summary/description, added author.
Set :spec as default task in Rakefile.
Created gemfiles for Rails 3 and Rails 4.

Removed static Gemfile -- now created with test app generator.
Rake :setup task relies as much as possible on test app generator.

Using hydra gem and hydra:install generator for dummy app (Fixes #17).