Linux Sed CSV – How to Turn Separate Lines into a Comma Separated List with Quoted Entries

I have the following data (a list of R packages parsed from a Rmarkdown file), that I want to turn into a list I can pass to R to install:

d3heatmap
data.table
ggplot2
htmltools
htmlwidgets
metricsgraphics
networkD3
plotly
reshape2
scales
stringr

I want to turn the list into a list of the form:

'd3heatmap', 'data.table', 'ggplot2', 'htmltools', 'htmlwidgets', 'metricsgraphics', 'networkD3', 'plotly', 'reshape2', 'scales', 'stringr'

I currently have a bash pipeline that goes from the raw file to the list above:

grep 'library(' Presentation.Rmd \
| grep -v '#' \
| cut -f2 -d\( \
| tr -d ')'  \
| sort | uniq

I want to add a step on to turn the new lines into the comma separated list. I've tried adding tr '\n' '","', which fails. I've also tried a number of the following Stack Overflow answers, which also fail:

• https://stackoverflow.com/questions/1251999/how-can-i-replace-a-newline-n-using-sed

This produces library(stringr)))phics) as the result.

• https://stackoverflow.com/questions/10748453/replace-comma-with-newline-in-sed

This produces ,% as the result.

• Can sed replace new line characters?

This answer (with the -i flag removed), produces output identical to the input.