Function isNull

isNull(value): value is null
Checks if value is null.
Parameters
- value: any
  The value to check.
Returns value is null
Returns true if value is null, else false.
Since
0.1.0
Example
```
isNull(null)
// => true

isNull(void 0)
// => false
```
- Defined in lodash/#isNull.tsx:16