title: can't align rows with kableExtra `cell_spec()`
body: <pre><code>---
  title: "Untitled"
  output: html_document
  ---
  
  ```{r setup, include=FALSE}
  knitr::opts_chunk$set(echo = TRUE)
  ```
  
  ```{r mtcars, warning=FALSE, message=FALSE, echo=FALSE, results='asis'}
  library(tidyverse)
  library(kableExtra)
  kable(mtcars %&gt;% 
          select(1:5) %&gt;% 
          head(10) %&gt;% 
          mutate(cyl = cell_spec(cyl, align = "r")), 
        "html", 
        escape = FALSE) %&gt;% 
    kable_styling("striped", "hover", full_width = TRUE) %&gt;%
    row_spec(c(1, 3), background = "yellow")
  ```
  </code></pre>
  
  <p>I <a href="https://cran.r-project.org/web/packages/kableExtra/vignettes/awesome_table_in_html.html" rel="nofollow noreferrer">follow the KableExtra guide</a> to align cells using the <code>cell_spec()</code> function. I am trying to <em>right</em> align my <code>cyl</code> column. But notice the column is not right aligned (image below).</p>
  
  <p>What went wrong?</p>
  
  <p><a href="https://i.stack.imgur.com/ROFiO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ROFiO.png" alt="kableExtra align"></a></p>