Invalid $family member with stan_polr

In the documentation for stanreg objects, object$family is supposed to be of class "family"; however, the object returned by stan_polr puts a character string there.

Example

example(stan_polr)
# --- (output not shown, produces an object named 'fit') ---
fit$family
## [1] "probit"

I suggest that instead this should be binomial(link = "probit"). I realize that "binomial" isn't quite right, but it is in a sense right with regard to each ordinal cut point, and the classes of objects should be as documented.

Operating System:

First part of sessionInfo():

R version 3.4.0 (2017-04-21)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows >= 8 x64 (build 9200)

Matrix products: default

locale:
[1] LC_COLLATE=English_United States.1252  LC_CTYPE=English_United States.1252   
[3] LC_MONETARY=English_United States.1252 LC_NUMERIC=C                          
[5] LC_TIME=English_United States.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] rstanarm_2.15.2  Rcpp_0.12.10     lsmeans_2.25-10  estimability_1.2 pscl_1.4.9      
[6] lattice_0.20-35  MASS_7.3-47 

Start by running the stan_polr example and inspecting the returned stanreg object's family member. Compare its value and class with the documented stanreg contract and determine the expected representation for ordinal models. Done means the family member and its documentation agree, with the example behavior covered by an appropriate check.