improve test of tasks "Ensure any remote plugins defined are present"

[roumano]

Actually, i can't run the role without any plugins on a machine :

ansible-playbook  ... --extra-var='sensu_remote_plugins=""'
TASK [sensu-client : Ensure any remote plugins defined are present] ********************************************************************************************************************
failed: [server] (item=) => {"changed": false, "cmd": "sensu-install -p ", "delta": "0:00:00.153447", "end": "2017-07-05 11:53:58.399445", "failed": true, "item": "", "rc": 1, "start": "2017-07-05 11:53:58.245998", "stderr": "/opt/sensu/embedded/lib/ruby/gems/2.3.0/gems/sensu-0.26.5/exe/sensu-install:38:in `cli_options': missing argument: -p (OptionParser::MissingArgument)\n\tfrom /opt/sensu/embedded/lib/ruby/gems/2.3.0/gems/sensu-0.26.5/exe/sensu-install:124:in `run'\n\tfrom /opt/sensu/embedded/lib/ruby/gems/2.3.0/gems/sensu-0.26.5/exe/sensu-install:136:in `<top (required)>'\n\tfrom /opt/sensu/embedded/bin/sensu-install:22:in `load'\n\tfrom /opt/sensu/embedded/bin/sensu-install:22:in `<main>'", "stderr_lines": ["/opt/sensu/embedded/lib/ruby/gems/2.3.0/gems/sensu-0.26.5/exe/sensu-install:38:in `cli_options': missing argument: -p (OptionParser::MissingArgument)", "\tfrom /opt/sensu/embedded/lib/ruby/gems/2.3.0/gems/sensu-0.26.5/exe/sensu-install:124:in `run'", "\tfrom /opt/sensu/embedded/lib/ruby/gems/2.3.0/gems/sensu-0.26.5/exe/sensu-install:136:in `<top (required)>'", "\tfrom /opt/sensu/embedded/bin/sensu-install:22:in `load'", "\tfrom /opt/sensu/embedded/bin/sensu-install:22:in `<main>'"], "stdout": "", "stdout_lines": []}

the when condition should be changed from

when: sensu_remote_plugins > 0

To :

when: sensu_remote_plugins

So we will get a skipping tasks :

TASK [sensu-client : Ensure any remote plugins defined are present] ********************************************************************************************************************
skipping: [server] => (item=) 

[smuth4]

sensu_remote_plugins expected to be a list (which defaults to being empty), if you override it to be an empty string python will return that "" > 0 is indeed true (gargbage in, garbage out). If when: sensu_remote_plugins works in both situations, I wouldn't mind a PR, but I don't see the need to fix what's not broken.