make tags additive to CLI tags

[peterneubauer]

in https://github.com/aphyr/riemann-tools/blob/master/lib/riemann/tools.rb#L58, the tags coming from something like

report(
      :service => "test",
      :metric => 1,
      :state => "ok",
      :tags => ["test"]
  )

are ignored if there also are command line tags set. I would suggest to combine them for better handling instead of silently ignoring them?

[jamtur01]

Hi @peterneubauer Any chance you could test the attached patch and make sure it works for you? Thanks!