Small edits to documentation.md.
Small edits to testing.Rmd.
Small edits to knitr.Rmd.
Converted Knitr lesson from RMarkdown to Markdown. I think it is better off in Markdown because none of the code chunks are evaluated, and it is easier to show knitr code examples this way.
Merge pull request #38 from jdblischak/doc-and-testing

Doc and testing