* Close evaluation stream for Nomad Job creation
when set event handler have been finished
* Remove evaluation event stream requests
by handling the events via the main Nomad event handler.
* #9 Implement routes to list, get and delete execution environments.
A refactoring was required to introduce the ExecutionEnvironment interface.
* Fix MR comments, linting issues and bug that lead to e2e test failure
* Add e2e tests
* Add unit tests
