Fix link to travis-ci
Create tmp dir per instance
Ensure config dir to 0640 mode.

plugin defines will follow later when updating them.
Updating plugin defines to use the file transfer feature
Change file mode to be more secure
First try to solve issue #37
Updating defines with better validation
Adding spec tests for defines
Correcting tmp dir creation
Update changelog and readme
Modify readme a bit for version table
Debian use tmpdir created by logstash::config

The previous value of `/var/logstash` wasn't created by the module. Now
matches the behaviour on RHEL.
Merge pull request #44 from alphagov/debian_tmpdir

Debian use tmpdir created by logstash::config
Update changelog and contributors
Update changelog and modulefile for release
Adding license