Update module to Puppet 4+ coding style

[johanfleury]

Hello @tobru.

First, I'd like to thank you for your work. Your module is really useful.

I identified multiple areas of improvement (mainly in order to update your module to Puppet 4+ coding style), and I was planning on creating some pull requests.

Here are some ideas:

• Update to Puppet 4+ data types and create aliases where necessary (e.g using structs for every hashes containing knot configuration).
• Create defined types for each part of the configuration and use concat to manage the base configuration file.
• Update the dependencies version boundaries.
• Maybe move to Hiera 5 in-module data (that would break compatibility with Puppet < 4.10).
• Fix Debian, knot out of j-bp: recurse => True of $default_storage will lead to "permission race" between knot and puppet #6.
• Fix errors thrown by puppet-lint checks (they can be fixed pretty easily):

$ puppet-lint --log-format "%{path}:%{line}: %{KIND}: [%{check}] %{message}" --no-autoloader_layout-check .
./manifests/init.pp:102: WARNING: [arrow_on_right_operand_line] arrow should be on the right operand's line
./manifests/init.pp:103: WARNING: [arrow_on_right_operand_line] arrow should be on the right operand's line
./manifests/install.pp:15: WARNING: [arrow_alignment] indentation of => is not properly aligned (expected in column 18, but found it in column 14)
./manifests/install.pp:10: WARNING: [arrow_alignment] indentation of => is not properly aligned (expected in column 16, but found it in column 19)
./manifests/install.pp:11: WARNING: [arrow_alignment] indentation of => is not properly aligned (expected in column 16, but found it in column 19)
./manifests/install.pp:12: WARNING: [arrow_alignment] indentation of => is not properly aligned (expected in column 16, but found it in column 19)
./manifests/install.pp:13: WARNING: [arrow_alignment] indentation of => is not properly aligned (expected in column 16, but found it in column 19)
./manifests/install.pp:14: WARNING: [arrow_alignment] indentation of => is not properly aligned (expected in column 16, but found it in column 19)
./manifests/install.pp:18: WARNING: [arrow_alignment] indentation of => is not properly aligned (expected in column 16, but found it in column 19)
./manifests/install.pp:22: WARNING: [arrow_on_right_operand_line] arrow should be on the right operand's line
./manifests/config.pp:60: WARNING: [file_ensure] ensure set to present on file resource
./manifests/service.pp:13: WARNING: [arrow_on_right_operand_line] arrow should be on the right operand's line
./manifests/params.pp:52: WARNING: [trailing_comma] missing trailing comma after last element
./manifests/params.pp:56: WARNING: [trailing_comma] missing trailing comma after last element

Before working on this and creating those PR, I wanted to confirm that you were ok with this and that you were still maintaining this module.

[johanfleury]

I made some of the proposed changes in the develop branch of my repository (this is in development, and isome of the changes might not be tested).