Tidy out some verbose debugs

beacon_node/beacon_chain/src/state_transition.rs

@@ -120,8 +120,6 @@ where
             );
         }
 
-        debug!("Block signature is valid.");
-
         /*
          * RANDAO
          */
@@ -136,8 +134,6 @@ where
             Error::BadRandaoSignature
         );
 
-        debug!("RANDAO signature is valid.");
-
         // TODO: check this is correct.
         let new_mix = {
             let mut mix = state.latest_randao_mixes