4.0.0 Mergeback

Prior to this commit, apt_key always sent auth basic header when source
came from http(s). This might fail for some webservers (e.g. Amazon S3)
when empty auth basic is sent.

Now apt_key only sends the auth basic header when userinfo can
be parsed from the URL.

This reverts commit part of 26608d1.

Revert removal of Evolving Web's attribution in NOTICE file

this module is not able to find a value for `$keyserver` when it is
included in postgresql, as stated in the ticket. this changes the module
back to using the params.pp model. we can revisit data in modules once
LTS moves up from 4.7.0. for now, we need the compatibility.

this module is not able to find a value for `$keyserver` when it is
included in postgresql, as stated in the ticket. this changes the module
back to using the params.pp model. we can revisit data in modules once
LTS moves up from 4.7.0. for now, we need the compatibility.

Test added to make sure when release is set to an empty string the
source file is rendered correctly.

Ensure release allows empty strings

https://tickets.puppetlabs.com/browse/MODULES-4913

Prior to this commit, apt_key always sent auth basic header when source
came from http(s). This might fail for some webservers (e.g. Amazon S3)
when empty auth basic is sent.

Now apt_key only sends the auth basic header when userinfo can
be parsed from the URL.

Please backport this to 2.4.x, since this is the release before incompatibility changes are made.

4.1.0 Release Prep