fix(bower): remove all versions from filepaths; Fix #494

This should do the trick.

https://github.com/rackerlabs/encore-ui/issues/494

Before:
```
$ grep -r '1.1.2' ./bower
./bower/bower.json:  "version": "1.1.2",
./bower/encore-ui-tpls.js: * Version: 1.1.2 - 2014-08-28
./bower/encore-ui-tpls.min.js: * Version: 1.1.2 - 2014-08-28
./bower/encore-ui-tpls.min.js.map:{"version":3,"file":"encore-ui-tpls-1.1.2.min.js","sources":["encore-ui-tpls-1.1.2.js"]...
./bower/encore-ui.css:/*# sourceMappingURL=encore-ui-1.1.2.css.map */
./bower/encore-ui.js: * Version: 1.1.2 - 2014-08-28
./bower/encore-ui.min.js: * Version: 1.1.2 - 2014-08-28
./bower/encore-ui.min.js.map:{"version":3,"file":"encore-ui-1.1.2.min.js","sources":["encore-ui-1.1.2.js"]...
```

After:
```
$ grep -r '1.1.2' ./bower
./bower/bower.json:  "version": "1.1.2",
./bower/encore-ui-tpls.js: * Version: 1.1.2 - 2014-08-28
./bower/encore-ui-tpls.min.js: * Version: 1.1.2 - 2014-08-28
./bower/encore-ui.js: * Version: 1.1.2 - 2014-08-28
./bower/encore-ui.min.js: * Version: 1.1.2 - 2014-08-28
```