Add rm command to delete results

internal/database/actions.go

@@ -122,6 +122,9 @@ func DeleteResult(sess sqlbuilder.Database, resultID int64) error {
 	var result Result
 	res := sess.Collection("results").Find("result_id", resultID)
 	if err := res.One(&result); err != nil {
+		if err == db.ErrNoMoreRows {
+			return err
+		}
 		log.WithError(err).Error("error in obtaining the result")
 		return err
 	}

internal/database/actions_test.go

@@ -8,6 +8,7 @@ import (
 	"testing"
 
 	"github.com/ooni/probe-cli/utils"
+	db "upper.io/db.v3"
 )
 
 func TestMeasurementWorkflow(t *testing.T) {
@@ -155,6 +156,11 @@ func TestDeleteResult(t *testing.T) {
 	if totalMeasurements != 0 {
 		t.Fatal("measurements should be zero")
 	}
+
+	err = DeleteResult(sess, 20)
+	if err != db.ErrNoMoreRows {
+		t.Fatal(err)
+	}
 }
 
 func TestNetworkCreate(t *testing.T) {