0,0.[000] format behaves differently in numeraljs and pynumeral

### Description

The numeraljs format "0,0.[000]" will only include decimals if necessary.  In pynumeral they are always returned.

### What I Did

```
>>> pynumeral.format(1, "0,0.[000]")
'1.000'
```

```
> const numeraljs = require('numeraljs')
> numeraljs(1).format('0,0.[000]');
'1'
```
