Adding crawler for HashiCorp's Terraform

[dpires]

This crawler downloads versions of Terraform from bintray.com for use with the terraform-plugin.

[orrc]

Oops, sorry, I meant to ask about this when I forked your plugin.

Anyway, looks good! The JSON output will be published to updates.jenkins-ci.org for the first time in ~21 hours (at the latest).

Since Terraform seems to package for a lot of OS/architecture combos, it might be worth looking at how other tool installer plugins automatically present only one (or at least fewer) version to the user, and automatically download the correct binary based on the build machine the job runs on, e.g. https://wiki.jenkins-ci.org/display/JENKINS/Go+Plugin

[dpires]

Thanks. I'll take a look at the Go plugin.