jtblin/angular-chart.js

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### Overview

Describe the issue. What is the issue and what did you expect?

Please make sure to review and check all of these items:

- [ ] Use latest version of the library
- [ ] Make sure you've included all the dependencies e.g Chart.js, angular, etc.
- [ ] Include a repro case, see below.


### Step to reproduce

**Ensure you add a link to a plunker, jsbin, or equivalent. Issues without repro steps may be closed immediately.** 

Here is a [jsbin template](https://jsbin.com/rukiyis/edit?html,js,output) for convenience.