Add version to graylog tmp repository file

[mlintern]

This would resolve #74

[CLAassistant]

All committers have signed the CLA.

[mariussturm]

@mlintern thanks for the contribution, would you mind signing the CLA?

[malcyon]

Closing and reopening to force TravisCI to run new test suite.

[malcyon]

@mlintern I think the step that installs the package needs to be updated, as well. The tests fail because it's still referencing the old version of the filename.

- name: "Graylog repository package should be installed"
  apt:
    deb: "/tmp/graylog_repository.deb"

[malcyon]

Thanks, @mlintern!