Borrow run.sh and Dockerfile from SBB Logagent image

[otisg]

From https://hub.docker.com/r/schweizerischebundesbahnen/logagent/

• run.sh: https://github.com/SchweizerischeBundesbahnen/docker-logagent/blob/master/bin/run.sh
• Dockerfile: https://github.com/SchweizerischeBundesbahnen/docker-logagent/blob/master/Dockerfile

... so we can build a Logagent image people can use.
We should probably add a link to it over at https://sematext.com/docs/logagent/#related-packages and also under Logagent > Install > Docker (doesn't exist yet)

[megastef]

Please note this PR: https://github.com/SchweizerischeBundesbahnen/docker-logagent/pull/4

[komljen]

@megastef please check this pull request #104