Side-effect of (0, obj.method)() is warned as no side-effect

Babel produces code that utilizes `(0, obj.method)()` in order to make a function call without the context being `obj` since `obj` is just a placeholder object for the methods that were imported.

When running code through Closure Compiler, it produces a warning:

```
JSC_USELESS_CODE: Suspicious code. This code lacks side-effects. Is there a bug? at line 165
dateStart = (0, _utilities.dateNow)();
```

That code does have the side-effect of calling `dateNow` without the context of `_utilities`.

The original code (before babel) stems from:

``` js
import { dateNow } from './utilities';
...
dateStart = dateNow();
```