Use here for referencing utilities with source()

[envest]

I am slightly concerned that, if invoked from the command line when not in the root directory of the repository, that it won't be able to find the util/ folder which we're now accustomed to solving with here or rprojroot.

Now that problem probably permeates the entire project, so any one instance might not be the biggest deal.

Originally posted by @jaclyn-taroni in #47 (comment)