Supported file operations for command tasks.
Supported file operations for command tasks.

Review: https://reviews.apache.org/r/70826/

reneploetz/mesos,reneploetz/mesos,chhsia0/mesos,abudnik/mesos,kaysoky/mesos,gsantovena/mesos,chhsia0/mesos,kaysoky/mesos,abudnik/mesos,reneploetz/mesos,dforsyth/mesos,Gilbert88/mesos,gsantovena/mesos,chhsia0/mesos,abudnik/mesos,gsantovena/mesos,chhsia0/mesos,Gilbert88/mesos,dforsyth/mesos,Gilbert88/mesos,dforsyth/mesos,abudnik/mesos,kaysoky/mesos,Gilbert88/mesos,kaysoky/mesos,Gilbert88/mesos,kaysoky/mesos,reneploetz/mesos,kaysoky/mesos,dforsyth/mesos,kaysoky/mesos,chhsia0/mesos,gsantovena/mesos,Gilbert88/mesos,dforsyth/mesos,abudnik/mesos,abudnik/mesos,gsantovena/mesos,dforsyth/mesos,Gilbert88/mesos,gsantovena/mesos,dforsyth/mesos,reneploetz/mesos,abudnik/mesos,chhsia0/mesos,chhsia0/mesos,gsantovena/mesos,reneploetz/mesos,reneploetz/mesos