adding travis integration

gents,

I added travis integration. 
I directly hooked up the ezinstall script.
https://travis-ci.org/soumith/torch7

One of you admins have to merge this, create a travis account (login with github) and enable travis builds for torch/torch7.

Some other things need to be fixed in ezinstall (checking return code for all the compile commands, which is not being done now), and I shall send in pushes to ezinstall