Update casperjs and phantomjs

In order to fix seabre/inviteyoself#5, We need to update PhantomJS to 1.9.8 first. It is a workaround for n1k0/casperjs#442.

In this PR, I also fix the version of CasperJS to 1.1.0-beta3 for stability.

```
$ heroku run bash
Running `bash` attached to terminal... up, run.6458
Add phantomjs/casperjs paths ...
~ $ casperjs --version
1.1.0-beta3
Unsafe JavaScript attempt to access frame with URL about:blank from frame with URL file:///app/vendor/casperjs/bin/bootstrap.js. Domains, protocols and ports must match.

~ $ phantomjs --version
1.9.8
```