Add ability to run tests with docker-compose

[mdedetrich]

This PR is about giving an SBT command that will run tests that will automatically start docker-compose then the run the tests and then shut it down. We do this using the https://github.com/Tapad/sbt-docker-compose library

So far things seem to work, however there appears to be a bug in sbt-docker-compose where its not running all specs2 tests, making an issue in upstream to see what can be the cause

[codecov-io]

Codecov Report

Merging #33 into master will increase coverage by 0.21%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master      #33      +/-   ##
==========================================
+ Coverage   70.61%   70.83%   +0.21%     
==========================================
  Files          20       20              
  Lines         456      456              
  Branches       10       10              
==========================================
+ Hits          322      323       +1     
+ Misses        134      133       -1

Impacted Files	Coverage Δ
...n/scala/org/zalando/kanadi/api/Subscriptions.scala	67.26% <0%> (+0.44%)	⬆️

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