test_compose_tar: Fix docker test

The docker phase always failed because `-ti` was passed even though the
the output was not a terminal. Moreover docker service isn't running by
default on RHEL-7, so it's necessary to start it first explicitly.

Related: rhbz#1720224

tests/cli/test_compose_tar.sh

@@ -15,6 +15,7 @@ CLI="${CLI:-./src/bin/composer-cli}"
 rlJournalStart
     rlPhaseStartSetup
         rlAssertExists /usr/bin/docker
+        rlRun -t -c "systemctl restart docker"
     rlPhaseEnd
 
     rlPhaseStartTest "compose start"
@@ -43,7 +44,7 @@ rlJournalStart
         rlRun -t -c "docker import $IMAGE composer/$UUID:latest"
 
         # verify we can run a container with this image
-        rlRun -t -c "docker run -it --rm --entrypoint /usr/bin/cat composer/$UUID /etc/redhat-release"
+        rlRun -t -c "docker run --rm --entrypoint /usr/bin/cat composer/$UUID /etc/redhat-release"
     rlPhaseEnd
 
     rlPhaseStartTest "Verify tar image with systemd-nspawn"