checkTypes: "natives" should be "primitives" (see notes below)

``` js
typeof true
"boolean"
```

OK

``` js
typeof 1
"number"
```

OK

``` js
typeof 'foo'
"string"
```

OK

``` js
typeof {}
"object"
```

NOT OK

``` js
[].constructor.name
"Array"
```

OK

``` js
new Date().constructor.name
"Date"
```

OK

``` js
/test/.constructor.name
"RegExp"
```

OK
