Better Error Messages for Lolopy

[WardLT]

The error message for lolopy when java isn't installed is: ValueError: invalid literal for int() with base 10: b''

We should make a better error message for this issue, and probably print warnings if you're running on Windows and the confidence intervals are not likely to work.

[maxhutch]

Here's another: https://github.com/CitrineInformatics/lolo/issues/191