release: upgrade zrender in package-lock.

package-lock.json

 {
   "name": "echarts",
-  "version": "4.5.0",
+  "version": "4.6.0",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -2334,9 +2334,9 @@
       "dev": true
     },
     "zrender": {
-      "version": "4.1.2",
-      "resolved": "https://registry.npmjs.org/zrender/-/zrender-4.1.2.tgz",
-      "integrity": "sha512-MJYEo1ZOVesjxYsfcGtPXnUREmh4ACMV08QZLGZ3S7D1xOd96iz3O6nf6pv5PHb5NSHkbizr7ChSIgtAGwncvA=="
+      "version": "4.2.0",
+      "resolved": "https://registry.npmjs.org/zrender/-/zrender-4.2.0.tgz",
+      "integrity": "sha512-YJ9hxt5uFincYYU3KK31+Ce+B6PJmYYK0Q9fQ6jOUAoC/VHbe4kCKAPkxKeT7jGTxrK5wYu18R0TLGqj2zbEOA=="
     }
   }
 }