Adding changes to prevent storeconfigs warnings.

If you are not using a storeconfig_backend or and storeconfigs is set to false in the case of some masterless puppet setups this module throws the following warning:

Warning: You cannot collect without storeconfigs being set on line 11 in file puppet/modules/ssh/manifests/hostkeys.pp
Warning: You cannot collect without storeconfigs being set on line 16 in file puppet/modules/ssh/manifests/hostkeys.pp
Warning: You cannot collect without storeconfigs being set on line 22 in file puppet/modules/ssh/manifests/hostkeys.pp
Warning: You cannot collect exported resources without storeconfigs being set; the collection will be ignored on line 4 in file puppet/modules/ssh/manifests/knownhosts.pp
Warning: Not collecting exported resources without storeconfigs
Warning: Not collecting exported resources without storeconfigs
Warning: Not collecting exported resources without storeconfigs

These warnings clutter up the puppet output and it would be great to remove them from the output. Without the contains syntax it adds a good amount more configuration wise but it doesn't through any parser errors with this configuration.

Im totally open to other suggestions on implementation. I would really like to use this module and this is currently a blocker for our implementation.