Rather than:

```ruby
 it { is_expected.to raise_error(Puppet::PreformattedError,
       `%r{Package name must be formatted as Yum::RpmName, not 'String'}
                     )
 }
```

use

```ruby
it { is_expected.to compile.and_raise_error(
   %r{Package name must be formatted as Yum::RpmName, not 'String'}
)}
```

Previously it was possible to use an arch of `undef` which
produced versionlock files for both yum and dnf that would
never match a package.

Change the default to `*` so versionlock lines always end in
`.*` unless an arch is specified in which case it is
`.x86_64` for instance.

De-duplicate start of string match character

Add dnf tag to metadata

The `yum list updates` command outputs diagnostic messages and then the
actual available updates both on stdout.  Depending on the installed yum
plugins, a variable number of diagnostic lines are emitted, and the
output is always formatted for humans, making it non-trivial to
distinguish useless and relevant lines.

Instead of ignoring the first line, match each line with a pattern
matching the following fields:
  - package: The name of the package for which an update is available,
    they are in the format <package-name>.<architecture>;
  - available_version: The version of the package available for update,
    ensure it starts with a digit;
  - repository: The repository containing the update

These fields are separated by a variable amount of space.  When a line
match this pattern, consider the package as relevant for update.

Improve extraction of available updates

versionlock must specify at least .* for arch.

Use simpler code for tests for expected failures

prepare release 4.3.0