Destroy runner on allocation stopped

Destroying the runner when Nomad informs us about its allocation being stopped, fixes the error of executions running into their timeout even if the allocation was stopped long ago.

internal/runner/inactivity_timer_test.go

@@ -1,8 +1,8 @@
 package runner
 
 import (
+	"github.com/openHPI/poseidon/internal/nomad"
 	"github.com/openHPI/poseidon/tests"
-	"github.com/stretchr/testify/mock"
 	"github.com/stretchr/testify/suite"
 	"testing"
 	"time"
@@ -15,18 +15,17 @@ func TestInactivityTimerTestSuite(t *testing.T) {
 type InactivityTimerTestSuite struct {
 	suite.Suite
 	runner   Runner
-	manager  *ManagerMock
 	returned chan bool
 }
 
 func (s *InactivityTimerTestSuite) SetupTest() {
 	s.returned = make(chan bool, 1)
-	s.manager = &ManagerMock{}
-	s.manager.On("Return", mock.Anything).Run(func(_ mock.Arguments) {
+	apiMock := &nomad.ExecutorAPIMock{}
+	apiMock.On("DeleteJob", tests.DefaultRunnerID).Return(nil)
+	s.runner = NewNomadJob(tests.DefaultRunnerID, nil, apiMock, func(_ Runner) error {
 		s.returned <- true
-	}).Return(nil)
-
-	s.runner = NewRunner(tests.DefaultRunnerID, s.manager)
+		return nil
+	})
 
 	s.runner.SetupTimeout(tests.ShortTimeout)
 }