test: add unit tests for the slotleader package

Author: rayanebel

.mockery.yaml

@@ -1,6 +1,15 @@
 with-expecter: true
 dir: "{{.InterfaceDir}}/mocks/"
 packages:
+  github.com/kilnfi/cardano-validator-watcher/internal/cardano:
+    interfaces:
+      CardanoClient:
+  github.com/kilnfi/cardano-validator-watcher/internal/cardano/cardanocli:
+    interfaces:
+      CommandExecutor:
   github.com/kilnfi/cardano-validator-watcher/internal/blockfrost:
     interfaces:
-      Client:
+      Client:
+  github.com/kilnfi/cardano-validator-watcher/internal/slotleader:
+    interfaces:
+      SlotLeader: