Problems rendering PDF data report from within markdown chunk

This little bit of code will produce an error if `output="html"` is removed or changed to `output="pdf"` when calling `makeDataReport()`.

    ```{r setup, include=FALSE}
    knitr::opts_chunk$set(echo = TRUE)
    ```

    ## R Markdown

    ```{r lalssldl}
    library(dataMaid)
    data(trees)
    makeDataReport(trees, output = "html",  replace=TRUE)
    ```
