Add tests for utils.R (`get_dep_version()`)

[rempsyc]

> covr::package_coverage()
lavaanExtra Coverage: 96.39%
R/utils.R: 0.00%
R/cfa_fit_plot.R: 92.31%
R/lavaan_var.R: 92.59%
R/nice_modindices.R: 93.94%
R/lavaan_extract.R: 96.61%
R/nice_fit.R: 98.94%
R/lavaan_cov.R: 100.00%
R/lavaan_defined.R: 100.00%
R/lavaan_reg.R: 100.00%
R/nice_lavaanPlot.R: 100.00%
R/nice_tidySEM.R: 100.00%
R/write_lavaan.R: 100.00%
R/zzz.R: 100.00%

And if possible and you have time bring the others to 100% too