Added Laravel risk of mass-assignment vulns

Vulnerability: Risk of mass-assignment
Vendor: laravel
Product: framework
CVE: none
Affected version: v4.1.0 to v4.1.28
Fixed version: v4.1.29
Reference: commit [#c942a1b](https://github.com/laravel/framework/commit/c942a1bc30999e3d7a5567f264bfc99c77843919)