ISO8601 date parse exception with no 'Z' specified

GSON version 2.7

According to ISO8601 standard, "2016-09-06T15:30:00" is a valid date (No 'Z' means local time), however we get exception trying to parse it:

```
Caused by: java.text.ParseException:
Failed to parse date ["2016-09-06T15:30:00']: No time zone indicator (at offset 0)
at com.google.gson.internal.bind.util.ISO8601Utils.parse(ISO8601Utils.java:274)
at com.google.gson.internal.bind.DateTypeAdapter.deserializeToDate(DateTypeAdapter.java:72)
```

Is GSON ISO8601 date implementations support only a subset of specification?