only use from for most only combinator

Author: jcouyang

lib/history.js

@@ -7,9 +7,9 @@ export default function initHistory(contextHistory){
           return acc;
         }, [])
         .multicast()
-  let travel = from(contextHistory.travel)
+  let travel = contextHistory.travel
   history.cursor = -1
-  history.travel = travel
+  history.travel = from(travel)
     .sample((offset,states)=>{
       let cursor = offset(states.length+history.cursor)
       if(cursor<states.length&&cursor>=0){