Not able to transcode the 3g2 extension file to mp4

[pavanpatil1]

Not able to transcode the 3g2 extension file to mp4.

Activity.foodmanianew.mp4

[umeshnevase]

@pavanpatil1

I've created PR's to allow files with 3g2 extensions.

#292
https://github.com/rtCamp/transcoder-laravel/pull/125