Some languages have environment or version managers such as RVM for Ruby, NVM for Node, or even Rackspace's DVM for Docker.
It's highly recommended to lock the Terraform version, so everyone in the team uses the same version, and updates can be painlessly handled. To do that, I suggest using a Terraform container, so we'll use here the one I use myself: sjourdan/terraform:<version> (from https://github.com/sjourdan/terraform-docker). But I understand replacing the simple terraform command by something such as docker run -it --rm -v `pwd`:/data sjourdan/terraform:0.7.3 can feel not so appealing. That's why we can use a common Makefile for each project using Terraform.
Using a common entry point for manipulating the infrastructure code helps a lot of sharing practices, enforcing policies, and integrating third-party services such as CI systems.
