Use git protocol instead of https for bower dependencies

Using the https protocol has caused some SSL issues with Bower:

```
Additional error details:
error: SSL certificate problem, verify that the CA cert is OK. Details:
error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed while accessing https://github.com/sdecima/javascript-detect-element-resize.git/info/refs?service=git-upload-pack
fatal: HTTP request failed
```