auto-test RSQLite dependent package example Rd and testthats

[ajdamico]

write an eanthony function that downloads a package source

replaces RSQLite with MonetDBLite throughout the text

runs devtools::check and the dontrun blocks

to confirm complete transferability btw the two packages

[ajdamico]

thinking a generalized version of this convey_devtools commit, but just one test per package and not a bunch. @hannesmuehleisen thoughts?

[ajdamico]

@hannesmuehleisen harder than i thought, but something like this? 6d007a8

[hannes]

curious what it will do