Remove moot `version` property from bower.json

Per bower/bower.json-spec@a325da3

Also their maintainer says they probably won't ever use it: http://stackoverflow.com/questions/24844901/bowers-bower-json-file-version-property

bower.json

 {
   "name": "shower",
-  "version": "1.0.15",
   "license": "MIT",
   "main": "index.html",
   "ignore": [