Releasing Packer v1.3.4

[adr...@hashicorp.com]

Howdy,

We are happy to announce that packer 1.3.4 is out and hope that this will warm up this very cold day. ☃️

This time packer comes with a lot of fixes and improvements and as usual, the changelog contains most of what happened.

Here is a couple of important changes:

* Users can now skip a post processor.

* make packer inspect not print sensitive variables.

Cheers,

The Packer Team.