Datastore refactor and added postgres tests (#259)

* fix apps & routes creation/update

* refactor datastore and added postgres tests

* added test-datastore and fixed circleci test

api/server/server_test.go

@@ -72,6 +72,7 @@ func getErrorResponse(t *testing.T, rec *httptest.ResponseRecorder) models.Error
 }
 
 func prepareBolt(t *testing.T) (models.Datastore, func()) {
+	os.Remove(tmpBolt)
 	ds, err := datastore.New("bolt://" + tmpBolt)
 	if err != nil {
 		t.Fatal("Error when creating datastore: %s", err)