Correct $PATH when using Composer and Node

I ran into an issue trying to use Behat (the shell could not find it) that I installed using `composer_packages`. I tracked this issue down to the `vendor/bin` directory being incorrectly specified in $PATH. The cause of this is that when installing Node it does not leave a newline in `.profile` but `composer.sh` needs one to work correctly.

So, I added a newline in the composer script and changed the echo to printf for consistency with the line below it.