Think through `compareVersion` edge cases

[colearendt]

compareVersion is definitely preferable to our current use of <. However, it is not without its strangeness:

as.integer(strsplit("1.8.0_181", "[.-]")[[1L]])
#> 1 8 NA
#> Warning: NAs introduced by coercion

The problem is that it only splits based on . and - (not _). As a result, some Java versions (i.e. 1.8.0_181) could not be compared properly. I may be way over-thinking this, but this should definitely be addressed if our Java requirement moves to something newer. (i.e. 1.8.0 or something like it).

Related to #103