chore: bump version to 0.8.6

0.8.5.1 was not a valid npm version number

package.json

@@ -1,6 +1,6 @@
 {
   "name": "opensheetmusicdisplay",
-  "version": "0.8.5.1",
+  "version": "0.8.6",
   "description": "An open source JavaScript engine for displaying MusicXML based on VexFlow.",
   "main": "build/opensheetmusicdisplay.min.js",
   "typings": "build/dist/src/",

src/OpenSheetMusicDisplay/OpenSheetMusicDisplay.ts

@@ -28,7 +28,7 @@ import { NoteEnum } from "../Common/DataObjects/Pitch";
  * After the constructor, use load() and render() to load and render a MusicXML file.
  */
 export class OpenSheetMusicDisplay {
-    private version: string = "0.8.5.1-release"; // getter: this.Version
+    private version: string = "0.8.6-release"; // getter: this.Version
     // at release, bump version and change to -release, afterwards to -dev again
 
     /**