matcher for less-restrictive comparison

[chris-rock]

This matcher implements a less-restrictive comparison. Currently, it was not possible to write integer comparison (#308)

describe sshd_config do
  its('Port') { should eq '22' } # works
  its('Port') { should eq 22 } # does not work
end

As highlighted in #307 some resources have case-insensitive values, and I would like tests write

describe auditd_conf do
   its('log_format') { should eq 'raw' } # works
   its('log_format') { should eq 'RAW' } # does not work
end

This PR introduces a new comparison matcher cmp, that covers those cases:

describe sshd_config do
  its('Port') { should cmp '22' }
  its('Port') { should cmp 22 } # works with integer
  its('Port') { should cmp 22.0 } # also understand float
  its('Port') { should_not cmp 22.1 }

  # case-insensitive
  its('LogLevel') { should cmp 'INFO' } 
  its('LogLevel') { should cmp 'info' }
  its('LogLevel') { should cmp 'InfO' }
end

[chris-rock]

fixes #307
fixes #308

[arlimus]

Could we establish cmp as the default matcher instead of eq for auditd_conf? Since the resource would be perfect for that! (i.e. just swap with eq + love the explanation!)

[chris-rock]

That is a great idea. I updated the docs.

[arlimus]

Really great new functionality, love this from a user's standpoint! Great feature, thank you @chris-rock 🎅 👍