build.py: adding R package "forecast"
build.py: adding R package "forecast"

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