Remove hyphen from pre versions

- It is intentionally invalid semver as pre versions should never be released
- UI and Mobile already do this

bower.json

 {
   "name": "jquery",
-  "version": "2.1.0-pre",
+  "version": "2.1.0pre",
   "ignore": [
     "**/.*",
     "build",

package.json

@@ -2,7 +2,7 @@
   "name": "jquery",
   "title": "jQuery",
   "description": "JavaScript library for DOM operations",
-  "version": "2.1.0-pre",
+  "version": "2.1.0pre",
   "main": "dist/jquery.js",
   "homepage": "http://jquery.com",
   "author": {