Round Infinity with a precision argument returns Infinity (#4272)

* Round Infinity with a precision argument returns Infinity

* Also making sure this is true for -Infinity
* Tested with _.round(), _.floor() and _.ceil()

* Switch to using isFinite to check if number should be rounded

* Add tests for rounding NaN now that there is an isFinite check

lodash.js

@@ -5406,7 +5406,7 @@
       return function(number, precision) {
         number = toNumber(number);
         precision = precision == null ? 0 : nativeMin(toInteger(precision), 292);
-        if (precision) {
+        if (precision && Number.isFinite(number)) {
           // Shift with exponential notation to avoid floating-point issues.
           // See [MDN](https://mdn.io/round#Examples) for more details.
           var pair = (toString(number) + 'e').split('e'),