Added some output files to ignore.
Added some output files to ignore.

plasma-umass/DoubleTake,plasma-umass/DoubleTake,bpowers/DoubleTake,bpowers/DoubleTake,plasma-umass/DoubleTake,plasma-umass/DoubleTake,bpowers/DoubleTake,bpowers/DoubleTake,bpowers/DoubleTake,plasma-umass/DoubleTake,plasma-umass/DoubleTake,plasma-umass/DoubleTake,bpowers/DoubleTake,bpowers/DoubleTake,bpowers/DoubleTake