Release v2.3.1

Fix issue of pipe operator

README.md

@@ -23,7 +23,7 @@ Angular directive for echarts (version >= 3.x) (The project is renamed from **an
 
 Latest version @npm:
 + `v3.2.0` for Angular >= 6
-+ `v2.3.0` for Angular < 6
++ `v2.3.1` for Angular < 6
 
 Github branches:
 + `master` for Angular >= 6
@@ -32,7 +32,7 @@ Github branches:
 A starter project on Github: https://github.com/xieziyu/ngx-echarts-starter
 
 # Latest Update
-+ 2018.07.24: v3.2.0 & v2.3.0:
++ 2018.07.24: v3.2.0 & v2.3.1:
   + New: [autoResize] now detects its container element's offset height.
   + Change: Resizing detection is now debounced.
 

src/lib/directive/ngx-echarts.directive.ts

@@ -5,7 +5,7 @@ import {
 import { ChangeFilter } from '../util/change-filter';
 import { Subject } from 'rxjs/Subject';
 import { Subscription } from 'rxjs/Subscription';
-import { debounceTime } from 'rxjs/operators';
+import 'rxjs/add/operator/debounceTime';
 
 declare var echarts: any;
 
@@ -110,7 +110,7 @@ export class NgxEchartsDirective implements OnChanges, OnDestroy, DoCheck {
         this._chart = this.createChart();
 
         // subscribe to _resize$ and debounced
-        this._resizeSub = this._resize$.pipe(debounceTime(50)).subscribe(() => {
+        this._resizeSub = this._resize$.debounceTime(50).subscribe(() => {
           if (this._chart) {
             this._chart.resize();
           }

src/lib/package.json

@@ -1,6 +1,6 @@
 {
   "name": "ngx-echarts",
-  "version": "2.3.0",
+  "version": "2.3.1",
   "description": "Angular directive for ECharts 3",
   "repository": "https://github.com/xieziyu/ngx-echarts.git",
   "author": "Xie, Ziyu <[email protected]>",