4497: `libssl-dev` is required to install on Ubuntu 16.04


What's the URL of the page containing the problem?


Describe the problem and any recommendations below.

Installed ReviewBoard new Ubuntu 16.04 instance by following the steps outlined in the link above today. Bo doing that pip install ReviewBoard failed with an openssl dependency error. This was fixable by installing libssl-dev.

The documentation should be updated to say that apt install libssl-dev is required.

Please provide any additional information below.