Fix command tasks with free play strategy

When using the free play strategy the command and shell tasks fail
logging due to an undefined variable. Fix that and add tests for it.

Change-Id: I830d64d6089f869dc5a0e3d4fe346e6480884793

tests/fixtures/config/remote-zuul-stream/git/org_project/playbooks/command.yaml

@@ -38,3 +38,11 @@
   handlers:
     - name: test handler
       command: echo "This is a handler"
+
+- hosts: all
+  strategy: free
+  tasks:
+    - name: Command task 1 within free strategy
+      command: echo "First free task"
+    - name: Command task 2 within free strategy
+      command: echo "Second free task"

tests/remote/test_remote_zuul_stream.py

@@ -96,6 +96,8 @@ class TestZuulStream(AnsibleZuulTestCase):
             self.assertLogLine('TASK \[Show contents of second file\]', text)
             self.assertLogLine('controller \| command test two', text)
             self.assertLogLine('controller \| This is a handler', text)
+            self.assertLogLine('controller \| First free task', text)
+            self.assertLogLine('controller \| Second free task', text)
             self.assertLogLine(
                 'controller \| ok: Runtime: \d:\d\d:\d\d\.\d\d\d\d\d\d', text)
             self.assertLogLine('PLAY RECAP', text)

zuul/ansible/callback/zuul_stream.py

@@ -210,6 +210,9 @@ class CallbackModule(default.CallbackModule):
 
         if self._play.strategy != 'free':
             task_name = self._print_task_banner(task)
+        else:
+            task_name = task.get_name().strip()
+
         if task.action in ('command', 'shell'):
             log_id = uuid.uuid4().hex
             task.args['zuul_log_id'] = log_id