This is the code I am using to install the package in R version 3.3.0 (2016-05-03).
install.packages("devtools")
devtools::install_github("twitter/AnomalyDetection")
library(AnomalyDetection)
This is what I get when I attempt to install package AnomalyDetection.
Downloading GitHub repo twitter/AnomalyDetection@master
from URL https://api.github.com/repos/twitter/AnomalyDetection/zipball/master
Error in curl::curl_fetch_memory(url, handle = handle) :
Problem with the SSL CA cert (path? access rights?)