Allow volumes without replicas

[glorpen]

This PR is strongly based on work in #92 but it is updated to current master and with one more test.

Fixes #88
Closes #92

[ekohl]

Looks like it makes sense but I wonder if $options needs a similar treatment. Could you have a look while you're at it?

[glorpen]

Not sure if it is what you wanted;
$options (and $_options) can be undef or array and is expected by code to be just that, I would only force string content with parameter type - Optional[Array[String]] but then gluster::volume::setting has non-typed parameter.

[ekohl]

I meant

puppet-gluster/manifests/volume.pp

Line 80 in 805e649

$_options = undef

[glorpen]

well, there was a bug :)

[ekohl]

I had a look and I think that #169 cleans up it a lot by using Puppet 4 language constructs. Haven't actually tested it so let's see if the tests pass :)

[glorpen]

@ekohl can we merge this? I think it would be nice since this PR contains changes from Dec 2016.

[ekohl]

Thanks!

[glorpen]

Big thanks :)