Terms don't match in node shutdown test

[studzien]

What are we doing to trigger the bug:

while (mix test test/fuzzy/partitions_test.exs:36); do sleep 1; done

What we expect:

• When running the fuzzy/partitions_test repeatedly, we expect it to pass every time.

What happens:

Some runs trigger the following test failure:

   1) test node shutdowns (Raft.Fuzzy.PartitionsTest)
     test/fuzzy/partitions_test.exs:36
     ** (RuntimeError) Terms don't match for  [s0: %{logs: [%Raft.Log.Entry{data: %Raft.Configuration{index: 0, new_servers: [], old_servers: [], state: :none}, index: 0, term: 0, type: :config}, %Raft.Log.Entry (...)

Additional info:

We have added the following debug output to try to understand what precisely
goes wrong during the failed test runs.

diff --git a/test/support/cluster.ex b/test/support/cluster.ex
index 25968bd..de65f99 100644
--- a/test/support/cluster.ex
+++ b/test/support/cluster.ex
@@ -87,6 +87,8 @@ defmodule Raft.Support.Cluster do
       {s, data}
     end

+    IO.inspect data, label: :data, limit: :infinity
+    IO.inspect commands, label: :commands, limit: :infinity
     verify_terms(data) && verify_logs(data, commands)
   end

We have also simplified the StreamData generator to make the command logs easier to read:

diff --git a/test/fuzzy/partitions_test.exs b/test/fuzzy/partitions_test.exs
index 6bee922..11e7bd4 100644
--- a/test/fuzzy/partitions_test.exs
+++ b/test/fuzzy/partitions_test.exs
@@ -10,7 +10,7 @@ defmodule Raft.Fuzzy.PartitionsTest do
   }

   def commands, do: one_of([
-    tuple({constant(:put), term()}),
+    tuple({constant(:put), integer()}),
     constant(:pop),
   ])

Attached is the full output of a failed test, run with the above changes in place.
terms-dont-match.log

/cc @pzel