A number of tests produce vararg parameter type warnings when enabled in Eclipse ("Inexact type match vararg arguments").

Apparently, this would cause a build error in the main build. Is it disabled in tests (build.gradle:553)? Should we enable the warning/error in tests?

```
Description Resource Location
Type null of the last argument to method mouseClick(MouseButton...) doesn't exactly match the vararg parameter type. Cast to MouseButton[] to confirm the non-varargs invocation, or pass individual arguments of type MouseButton for a varargs invocation. RobotTest.java line 491
Type null of the last argument to method mousePress(MouseButton...) doesn't exactly match the vararg parameter type. Cast to MouseButton[] to confirm the non-varargs invocation, or pass individual arguments of type MouseButton for a varargs invocation. RobotTest.java line 447
Type null of the last argument to method mouseRelease(MouseButton...) doesn't exactly match the vararg parameter type. Cast to MouseButton[] to confirm the non-varargs invocation, or pass individual arguments of type MouseButton for a varargs invocation. RobotTest.java line 469
Type String[] of the last argument to method format(String, Object...) doesn't exactly match the vararg parameter type. Cast to Object[] to confirm the non-varargs invocation, or pass individual arguments of type Object for a varargs invocation. FileReaderTest.java line 229
```