Recreate vignette on latest public versions of lubridate and pkgnet

[bburns632]

We need to recreate the vignette with specific versions of BOTH lubridate and pkgnet and update the "A Deeper Look" with instructions utilizing devtools::install_version() (or some other more R way to install specific versions) to replicate the analysis.

This will prevent #189 from happening again in the future. Considering that #181 is updating the content to align with itself, we can save this vignette update until after the next pushed version to github

[jayqi]

I actually disagree with pegging pkgnet version. I think in general, if we're making changes that we anticipate to affect the vignette static content, it's the responsibility of that PR contributor to update the vignette. Additionally, I think before we do a release, we should check the vignette. It makes more sense to me for our vignette to be up-to-date with the latest release of pkgnet.