Initial 0 on percentage not formatted

[faelcorreia]

Issue #52

[assisrafael]

I had tested your patch and found that your test pass even if your bug fix is not used.
The problem is with your model value: '0'
In JavaScript !'0' === false so this case is covered.
However, if you change your model value to 0 the directive throws an error.
The main problem is that the formatter needs to convert the number to string before trying to format it.

[assisrafael]

Take a look at the tests that I included into the develop branch: 55e1eb2

[faelcorreia]

I see. Would be right to call toString on value before return it?

[assisrafael]

You had tried it?

[assisrafael]

Fixed in 5d0f456