Expose package and service ensure params

#### Add package_ensure param
So that consumers of this module can specify a specific package version or
"latest". Modified the test to call the outer class where our public params
are, as we've done for other modules like puppet-gor.

#### Add service_ensure param
So that consumers of this module can stop the service if they wish. Modified
the test to call the outer class where our public params are, as we've done
for other modules like puppet-gor.

#### Release 0.1.0