add more inverses

[aplavin]

I personally just need logit/logistic, but others also make sense to add

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 5 lines in your changes missing coverage. Please review.

Project coverage is 62.73%. Comparing base (d8ed2dc) to head (945dd52).

Files with missing lines	Patch %	Lines
ext/StatsFunsInverseFunctionsExt.jl	0.00%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #169      +/-   ##
==========================================
- Coverage   63.22%   62.73%   -0.50%     
==========================================
  Files          14       14              
  Lines         639      644       +5     
==========================================
  Hits          404      404              
- Misses        235      240       +5     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[devmotion]

These functions are defined in LogExpFunctions, not in StatsFuns. There the inverses are defined as well: https://github.com/JuliaStats/LogExpFunctions.jl/blob/289114f535827c612ce10c01b8dec9d3a55e4d15/ext/LogExpFunctionsInverseFunctionsExt.jl#L6-L14

[aplavin]

Wow, wonder how I managed to miss that :) I was 99% sure those inverses don't work, but clearly they do. Thanks!