Change dependencies for RDF 1.1 requiring at least Ruby 1.9.2.
Add travis config.
Update status tags in README
Add Gemfile and Travis config.
Merge remote-tracking branch 'refs/remotes/origin/master'

Conflicts:
	.gemspec
	.gitignore
	.travis.yml
	Gemfile
	README.md
	VERSION
	lib/rdf/json/version.rb