Add RMarkdown support.

[brianlukoff]

No description provided.

[brianlukoff]

Thanks! Could you republish to npm?

[balupton]

For the future, each push to master is published to the next tag on npm, which is made possible via https://github.com/bevry/awesome-travis/blob/master/scripts/node-publish.bash which can be automatically configured with the rest of bevry's best practices via https://github.com/bevry/boundation - each week or so we also have an automated script to run boundation on all our repos to do automatic version bumps with the latest practices and deps

That said we should do more to document this behaviour in our readmes