package can't be installed

## Summary

- Package `assertive` has been [removed from CRAN](https://cran.r-project.org/web/packages/assertive/index.html)
- Package `rdrop2` has also been [removed from CRAN](https://cran.r-project.org/web/packages/rdrop2/index.html), although it [still exists on GitHub](https://github.com/karthik/rdrop2)
- Because of this, packages that depend on `rdrop2` can't be installed automatically (with, e.g., `devtools::install_github("BAAQMD/droptools")` or `pak::pak("BAAQMD/droptools")`; installation will fail
- This package depends on `BAAQMD/droptools`

Review tbltools's package dependency declarations and the installation path used by devtools::install_github or pak::pak; identify how the dependency on BAAQMD/droptools leads to the CRAN-removed packages. Completion should be demonstrated by installing tbltools successfully without the current assertive or rdrop2 failure.

Written by the indexing model from the issue text.