Match thing VariableName with dashboard variable_id (#128)

When a dashboard is extracted the `variable_id` fields are filled with property `VariableName`. However when they're imported to create a dashboard the field `name` is used instead.

* Match thing variable_name with dashboard variable_id

* Fix dashboard with variable tests

Author: pennam

internal/template/dashboard.go

@@ -75,7 +75,7 @@ func getVariableID(thingID string, variableName string, fetcher ThingFetcher) (s
 	}
 
 	for _, v := range thing.Properties {
-		if v.Name == variableName {
+		if v.VariableName == variableName {
 			return v.Id, nil
 		}
 	}

internal/template/load_test.go

@@ -149,15 +149,15 @@ func (t *thingShowTest) ThingShow(thingID string) (*iotclient.ArduinoThing, erro
 	if thingID == thingOverriddenID {
 		return &iotclient.ArduinoThing{
 			Properties: []iotclient.ArduinoProperty{
-				{Id: switchyOverriddenID, Name: "switchy"},
+				{Id: switchyOverriddenID, VariableName: "switchy"},
 			},
 		}, nil
 	}
 	return &iotclient.ArduinoThing{
 		Properties: []iotclient.ArduinoProperty{
-			{Id: switchyID, Name: "switchy"},
-			{Id: relayID, Name: "relay_2"},
-			{Id: blinkSpeedID, Name: "blink_speed"},
+			{Id: switchyID, VariableName: "switchy"},
+			{Id: relayID, VariableName: "relay_2"},
+			{Id: blinkSpeedID, VariableName: "blink_speed"},
 		},
 	}, nil
 }