Add support for artifacts on the build enpoint
Bump gem version
Update README.md
Merge branch 'master' into artifacts_endpoint

Conflicts:
	circleci.gemspec
update gemspec version
Make more detailed test for artifact method
Merge branch 'artifacts_endpoint' of github.com:janstenpickle/circleci into artifacts_endpoint
Do not change circle version number
Add yardoc for new artifacts method
Merge pull request #3 from janstenpickle/artifacts_endpoint

Artifacts method on build endpoint