Dash docs argument length error  #232

An error occurs when running the Dash R docs locally with the dev branch of dashr , although they run fine on the master branch. I've narrowed it down to this commit which is where the following error appears when we run server:

error: All unnamed arguments must be length 1 from NULL

The error has been traced to this commit and involves the glue::glue function call, and how some arguments are being handled with glue. Somewhat blocking to the pattern matching docs chapter issue as the docs will not run with the latest version of Dash for R.