Updating .ruby-version to 2.0.0-p247

There's no 2.0.0 release of ruby, closest is 2.0.0-p0
sh/test: use bundler to ensure correct gem-version is loaded
sh/install-etcd: halt at any error to ensure sanity
Removing Gemfile.lock as per http://yehudakatz.com/2010/12/16/clarifying-the-roles-of-the-gemspec-and-gemfile/
Loosening version-dependency on multi_json to be compatible with most other gems
Merge pull request #6 from rud/cleanup-test-environment

Cleanup test environment