include terraform in published package name

    When I visit http://www.terraform.io/downloads.html
    And I download the zip file for my platform
    I get a file on disk called '0.1.0_linux_amd64.zip'
    And I am unable to determine what this is at a later date
    And I can not determine it from the '0.6.0_linux_amd64.zip'
    Which turns out to be Packer. 

This simple change adds the project name to the archive.
This was done with zero knowledge of using bintray and is untested as I have no bintray account etc.