(maint) 1.1.0 Merge Back

This commit bumps the upper boundary of the stdlib dependency.

It should help avoid conflicts (librarian-puppet) such as:

[Librarian]   Module puppetlabs-lvm found versions: 1.1.0, 1.0.1, 1.0.0, 0.9.0, 0.8.0, 0.7.0, 0.6.0, 0.5.0, 0.4.0, 0.3.3, 0.3.2, 0.3.1, 0.3.0, 0.2.0, 0.1.2, 0.1.1, 0.1.0, 0.0.1
[Librarian]     Checking puppetlabs-lvm/1.1.0 <https://forgeapi.puppetlabs.com>
[Librarian]       Resolved puppetlabs-lvm (< 2.0.0, >= 1.0.0) <https://forgeapi.puppetlabs.com> at puppetlabs-lvm/1.1.0 <https://forgeapi.puppetlabs.com>
[Librarian]   Resolved puppetlabs-lvm (< 2.0.0, >= 1.0.0) <https://forgeapi.puppetlabs.com>
[Librarian] Conflict between puppetlabs-stdlib (< 5.0.0, >= 4.13.1) <(no source specified)> and puppetlabs-stdlib/5.1.0 <https://forgeapi.puppetlabs.com>

We need to use stdlib >= 5.1 for compatibility with puppet 6.

Unfortunately you've deleted the changes, merged in #193 with the new release 1.1.0.

Error: Facter: error while resolving custom facts in /opt/puppetlabs/puppet/cache/lib/facter/lvm_support.rb: execution of command "vgs -o name --noheadings 2>/dev/null" failed: command not found.

(maint) Removed test code that missed review

Don't execute the lvm commands when not supported. #193

(maint) - Fix rubygems-update for ruby < 2.3

Added test matrix for Puppet 6

Allow puppetlabs-stdlib versions >= 5.0

(MODULES-8417) - 1.2.0 Pre Release