add regexp to cmp matcher

[arlimus]

i.e. 123 should { cmp /2+/ }

[alexpop]

I made a small change to support the Integer example in the PR request. It will also provide the cmp matching capabilities for this use-case: #666 👿

Like:

describe file('/etc/shadow') do
  its('mode') { should cmp /0(0|4)00/ }
end

UPDATE:
^ because mode returns Integer at the moment, the regex will have to be adapted for Integers, like:

describe file('/etc/shadow') do
  its('mode') { should cmp /^(256|0)$/ }
end

or converted to octal string:

describe file('/etc/shadow').mode.to_s(8) do
  it { should cmp /(0|4)00/ }
end

or for a way to get the file mode in octal.

[alexpop]

While updating the integration tests for cmp, I've noticed that there were a bunch of other tests failing:

For example:

bundle exec kitchen verify default-centos-67
...
Finished in 1.43 seconds (files took 1.22 seconds to load)
200 examples, 20 failures, 11 pending

Failed examples:

rspec  # Apache Config /etc/httpd/conf/httpd.conf LogLevel should eq "warn"
rspec  # Apache Config /etc/httpd/conf/httpd.conf MaxKeepAliveRequests should eq "100"
rspec  #  should cmp 0
rspec  # SSH Configuration Port should eq "22"
rspec  # SSH Configuration Port should cmp "22"
rspec  # SSH Configuration Port should cmp 22
rspec  # SSH Configuration Port should cmp 22.0
rspec  # SSH Configuration Port should not cmp 22.1
rspec  # SSH Configuration LogLevel should eq "INFO"
rspec  # SSH Configuration LogLevel should cmp "INFO"
rspec  # SSH Configuration LogLevel should cmp "info"
rspec  # SSH Configuration LogLevel should cmp "InfO"
rspec  # /etc/group users should include "root"
rspec  # #<Inspec::Resources::EtcGroupView:0x007f90a621f6b8> users should include "root"
rspec  # File /tmp/file mode should cmp "0765"
rspec  # File /mnt/iso-disk should be mounted
rspec  # File /mnt/iso-disk should be mounted
rspec  # Mount /mnt/iso-disk options should eq ["ro"]
rspec  # PostgreSQL query: show ssl; output should eq "on"
rspec  # User root groups should include ["root"]

Are integration tests not run on PRs?

[srenatus]

@alexpop: currently, they require vagrant and are not run automatically at all. Improvements needed! 👍

[arlimus]

@alexpop let's address the missing tests separately, we might need a workaround with travis here...

Everything else looks great 👍 Thank you for the improvements

[fcaviggia]

Awesome work! These are great improvements!