Removed version number from bower.json, it's not used by bower and can be found in package.json

bower.json

@@ -1,6 +1,5 @@
 {
   "name": "vis",
-  "version": "4.12.1-SNAPSHOT",
   "main": ["dist/vis.min.js", "dist/vis.min.css"],
   "description": "A dynamic, browser-based visualization library.",
   "homepage": "http://visjs.org/",

misc/how_to_publish.md

@@ -5,7 +5,7 @@ This document describes how to publish vis.js.
 
 ## Build
 
-- Change the version number of the library in both `package.json` and `bower.json`.
+- Change the version number of the library in `package.json`.
 - Open `HISTORY.md`, write down the changes, version number, and release date.
 - Build the library by running: