Changes .travis.yml to use Travis "stages" and "cache" to isolate time-consuming tasks in a sequence of dependent jobs (notably building the R package cache), and to avoid building the VE packages more than once in the overall build. Implements identical functionality to the existing .travis.yml, but runs in roughly 1/3 the time without ever timing out (so no more bogus check-ins to force a cache rebuild).
Changes .travis.yml to use Travis "stages" and "cache" to isolate time-consuming tasks in a sequence of dependent jobs (notably building the R package cache), and to avoid building the VE packages more than once in the overall build. Implements identical functionality to the existing .travis.yml, but runs in roughly 1/3 the time without ever timing out (so no more bogus check-ins to force a cache rebuild).
See https://github.com/VisionEval/VisionEval-dev, where this change originated for ongoing updates.