Merge pull request #820 from fassadlr/fixfedmembers

Can inject null IPoaMiner into FederationController

Author: fassadlr

src/Stratis.Bitcoin.Features.PoA/Voting/FederationController.cs

@@ -30,8 +30,8 @@ public FederationController(
             VotingManager votingManager,
             Network network,
             IFederationHistory federationHistory,
-            IPoAMiner poAMiner,
-            ReconstructFederationService reconstructFederationService)
+            ReconstructFederationService reconstructFederationService,
+            IPoAMiner poAMiner = null)
         {
             this.chainIndexer = chainIndexer;
             this.federationManager = federationManager;