build/ansible: install Richard McElreath's statistical rethinking package
build/ansible: install Richard McElreath's statistical rethinking package

sagemathinc/smc,tscholl2/smc,tscholl2/smc,tscholl2/smc,DrXyzzy/smc,tscholl2/smc,sagemathinc/smc,sagemathinc/smc,DrXyzzy/smc,DrXyzzy/smc,sagemathinc/smc,DrXyzzy/smc,tscholl2/smc