Environment.getProperty() method cannot process list items

```yaml
first:
  second: i,like,fish
```

the yaml config above can be processed when following code is executed

```java
List<String> values = environment.getProperty("key", (List<String>) List.class)
```

however, following yaml config cannot be processed by the code snippet above

```yaml
first:
  second:
    - i
    - like
    - fish
```

