Removed unused dependency "he"

package.json

@@ -54,7 +54,6 @@
     "dagre-d3": "^0.6.4",
     "entity-decode": "^2.0.2",
     "graphlib": "^2.1.7",
-    "he": "^1.2.0",
     "khroma": "^1.1.0",
     "moment-mini": "^2.22.1",
     "stylis": "^3.5.2"

src/mermaid.js

@@ -2,7 +2,6 @@
  * Web page integration module for the mermaid framework. It uses the mermaidAPI for mermaid functionality and to render
  * the diagrams to svg code.
  */
-// import { decode } from 'he';
 import decode from 'entity-decode/browser';
 import { log } from './logger';
 import mermaidAPI from './mermaidAPI';