core: initial commit for logger (#228)

* Replace "log.*" with logger.
* Add simple logger to log with log package.
* Add debug logs to all calls to these interfaces:
   - core.Application
   - core.Governance
   - core.Network
* Add Stringer to these types:
   - types.DKGComplaint
   - types.AgreementResult
   - types.DKGMasterPublicKey
   - types.DKGFinalize

1 files changed, 2 insertions, 1 deletions

diff --git a/core/lattice_test.go b/core/lattice_test.go
index 5c06b92..a508f2b 100644
--- a/core/lattice_test.go
+++ b/core/lattice_test.go
@@ -121,7 +121,8 @@ func (s *LatticeTestSuite) newTestLatticeMgr(
 			NewAuthenticator(prvKey),
 			app,
 			app,
-			db)}
+			db,
+			&common.NullLogger{})}
 }
 
 func (s *LatticeTestSuite) TestBasicUsage() {