Describe the bug
The Vault package is broken, causing apt commands to fail. This is the same issue reported for Consul here.

To Reproduce
Steps to reproduce the behavior:

$ curl -fsSL https://apt.releases.hashicorp.com/gpg | sudo apt-key add -
$ sudo apt-add-repository "deb [arch=amd64] https://apt.releases.hashicorp.com $(lsb_release -cs) main"
$ sudo apt-get update && sudo apt-get install vault

This will produce output containing a message like so:

Reading package lists...
    STDERR: E: Encountered a section with no Package: header
    E: Problem with MergeList /var/lib/apt/lists/apt.releases.hashicorp.com_dists_bionic_main_binary-amd64_Packages.lz4
    E: The package lists or status file could not be parsed or opened.

Expected behavior
Vault is installed by the packaging system.

Environment:

• Vault Server Version (retrieve with vault status): Attempting to install 1.3.0 (yeah, we know it's old), but version doesn't matter.
• Vault CLI Version (retrieve with vault version): N/A as install fails
• Server Operating System/Architecture: Ubuntu 18.04, in a container in this context, but it actually fails anywhere.

Vault server configuration file(s): N/A
Additional context
Add any other context about the problem here.
This appears to be a general issue with the package files for Hashicorp's repo, which we switched to so we could get more recent versions than the OS provided packages.