Kubernetes relies on the PrevKV() option in the watches it opens
against etcd. This commit adds a robustness test to validate the
same.
A watch response returned with PrevKV() is valid if:
The value in current event's prevKV matches the previous
event's value of the same key if this is not a create event.
There are cases where there can be a prevKV for a create event
as well, for example if a watch is opened after the key is creatd.
Since we don't simulate for that, we don't check for that.
Further, this adjusts revision numbers such that we can successfully create
a new replay. Needed now since we will have unit tests with
and without PrevKV co-existing and we requite creation of a
new replay everytime we validate PrevKV.
We also regenerate test data with so that prevKV exists in it
Signed-off-by: Madhav Jivrajani <madhav.jiv@gmail.com>
