Show Step Status for TaskRun Describe

[danielhelfand]

tkn tr describe tr_name will show the names of steps as part of a task run, but it does not show the status of the steps. This was originally excluded from #303 because of not fully knowing how to check whether the step status was available yet.

Expected Behavior

Show step status of steps for task run describe command:

Steps
NAME    STATUS
step1   Succeeded
step2   Running

Actual Behavior

Steps
NAME
step1
step2

Steps to Reproduce the Problem

Run tkn tr describe with any taskrun

[danielhelfand]

/kind feature

[danielhelfand]

/assign