Add ensure parameter to jenkins::slave

[carlossg]

Allows running the slave manually instead of a service, useful in Docker for instance

[rtyler]

@carlossg could I convince you to add an rspec-puppet example or two to verify that passing a class parameter into the jenkins::slave class gets to the service correctly?

[carlossg]

Added. The travis build is broken from the previous commit.
You may consider switching rcov to simplecov. rcov doesn't work in 1.9 and it's a native gem that needs to be compiled https://github.com/relevance/rcov

[jenkinsadmin]

Thank you for a pull request! Please check this document for how the Jenkins project handles pull requests

[carlossg]

do you need anything else?

[carlossg]

rebased

[justinclayton]

it's failing presumably only because of the pending test?

[carlossg]

puppet-lint error. Previous builds used puppet-lint 0.3.2, this one used 1.0.1

The command "rake lint" exited with 1.

[carlossg]

lint issues fixed in #167