Add UTC to allowed capitalized functions

This commit adds `Date.UTC` to allowed capitalized functions in the `new-cap` rule.

This fixes a problem where the `Date.UTC` function is flagged because it begins with a capital letter.

Example code that was flagged by `new-cap` but should pass without a warning:
```js
var timestamp = Date.UTC(2004, 02, 14);
```

Can you add a test for `var b = UTC()`. That will ensure we're testing the edge case I mentioned.