[Issue]: isNumber ignores javascript values: -Infinity & Infinity and returns false

Couple of issues I encountered when using this library in my project:

`isNumber` - returns `false` for javascript numeric values: `-Infinity & Infinity` and for numbers created using `new Number(..)` wrapper;

`isBoolean` & `isString` returns `false` for objects created using new keywords.
i.e., `new String('asdf') & new Boolean()`

@flexdinesh, please let me know if this need to be handled