refactor: StateSynchronizer no longer does diff

packages/state/package.json

@@ -5,7 +5,6 @@
   "author": "cha0s",
   "license": "MIT",
   "dependencies": {
-    "immutable": "4.0.0-rc.12",
-    "immutablediff": "0.4.4"
+    "immutable": "4.0.0-rc.12"
   }
 }

packages/state/synchronizer.js

@@ -1,5 +1,4 @@
 import * as I from 'immutable';
-import immutablediff from 'immutablediff';
 
 export class StateSynchronizer {
 
@@ -9,18 +8,6 @@ export class StateSynchronizer {
     this.tick();
   }
 
-  diff(previousState) {
-    // Take a pure JS diff.
-    const steps = immutablediff(
-      previousState,
-      this._state
-    ).toJS();
-    if (0 === steps.length) {
-      return undefined;
-    }
-    return steps;
-  }
-
   static nextStep(step) {
     const {path, op, value} = step;
     const parts = path.split('/');
@@ -33,10 +20,6 @@ export class StateSynchronizer {
     }];
   }
 
-  static isStepUpdate(step) {
-    return -1 !== ['add', 'replace'].indexOf(step.op);
-  }
-
   patchState(patch) {
     const stepMap = {};
     for (const {op, path, value} of patch) {