Updated rake to rely on bundler/gem_tasks and rake/testtask

* Restructured gemspec
* Switched versioning to match `bundler gem` conventions
Merge branch 'master' into bundle-gem-tasks

* master:
  Guarantee latest bundler
  Added explicit script config to .travis.yml
  Fixed tests for Rails 4
  Added .travis.yml build matrix
  Added config.rb for Rakefile usage

Conflicts:
	test/helper.rb
Removed default script override in travis.yml
Switched to generating large test file with pure ruby
Merge pull request #43 from ahoward/bundle-gem-tasks

Rely on bundler/gem_tasks and rake/testtask