Legends in D3 Charts not rendering properly in Macbook Pro 15'

### Issue type

**I'm submitting a ...** (check one with "x")

* [ x ] bug report
* [ ] feature request
* [ ] question about the decisions made in the repository

### Issue description

**Current behavior:**

Legend in D3 charts not rendering properly in Macbook Pro 15'

**Expected behavior:**

Legend in D3 charts should render correctly

**Steps to reproduce:**

Open the below URL from a 15' Macbook Pro
http://akveo.com/ngx-admin/pages/charts/d3