task/install: run 'yum ... install' the right way

task/install: run 'yum ... install' the right way

after cd1cef6, we install rpm packages like

2018-10-25T06:31:33.578 INFO:teuthology.orchestra.run.smithi076:Running:
"sudo yum -y '' install '' '' libcephfs_jni1"
...
2018-10-25T06:31:34.180
INFO:teuthology.orchestra.run.smithi076.stderr:No such command: . Please
use /bin/yum --help
2018-10-25T06:31:34.193 DEBUG:teuthology.orchestra.run:got remote
process result: 1

which fails the qa run on rpm based distros.

in this change, the command line args are passed in itertools.chain(),
because orchestra.run.quote() takes an iterable which contains string or
Raw.

Signed-off-by: Kefu Chai <kchai@redhat.com>