Add support for Ubuntu 20.04

[amateo]

Since Ubuntu 16.04 the plugins package is monitoring-plugins-basic but
a metapackage named nagios-plugins-basic (which install the former) is
maintained. In Ubuntu 20.04 this metapackage does not exist.

[amateo]

I don't know why travis is failing in all tests with errors which are not related with any change I have made.

Do you have any idea?

[ghoneycutt]

Thanks for the contribution! We need an update the ubuntu portion of the spec test that shows that the new package name is used on Ubuntu 20.04. See https://github.com/ghoneycutt/puppet-module-nrpe/blob/master/spec/classes/init_spec.rb

There should also be an update to the README.md (https://github.com/ghoneycutt/puppet-module-nrpe#compatibility) and to the metadata.json

[amateo]

I have patched the files you asked for.

But there are still problems with integration tests. I have no idea, because all tests are failling and reported problems have no relation with my changes.

[amateo]

@ghoneycutt, any idea for the travis errors?

They are errors like:

ERROR:  Error installing rubygems-update:

	There are no versions of rubygems-update (= 3.1.4) compatible with your Ruby & RubyGems

	rubygems-update requires Ruby version >= 2.3.0. The current ruby version is 1.9.1.

ERROR:  While executing gem ... (Errno::ENOENT)

    No such file or directory - /home/travis/.rvm/gems/ruby-1.9.3-p551/gems/rubygems-update-2.7.8

The command "gem update --system" failed and exited with 1 during .

that are not (apparently) related with my changes.