See https://api.travis-ci.org/v3/job/688142918/log.txt
E> clang++ -mmacosx-version-min=10.13 -std=gnu++14 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I'/Library/Frameworks/R.framework/Versions/4.0/Resources/library/Rcpp/include' -I'/Library/Frameworks/R.framework/Versions/4.0/Resources/library/RcppEigen/include' -I'/Library/Frameworks/R.framework/Versions/4.0/Resources/library/StanHeaders/include' -I'/Library/Frameworks/R.framework/Versions/4.0/Resources/library/BH/include' -I'/Library/Frameworks/R.framework/Versions/4.0/Resources/library/rpf/include' -I/usr/local/include -mmacosx-version-min=10.7 -fPIC -Wall -g -O2 -c Compute.cpp -o Compute.o
E> Compute.cpp:20:10: fatal error: 'random' file not found
E> #include <random>
E> ^~~~~~~~
E> 1 error generated.
E> make[1]: *** [Compute.o] Error 1
@jeroen @jimhester Please suggest a solution. Thank you.