This fix #133

As mentioned in MDN: stroke-linecap it is the expected behavior of svg stroke-linecap for both round and square.

The round value indicates that at the end of each subpath the stroke will be extended by a half circle with a diameter equal to the stroke width. On a zero length subpath, the stroke consists of a full circle centered at the subpath's point.

The square value indicates that at the end of each subpath the stroke will be extended by a rectangle with a width equal to half the width of the stroke and a height equal to the width of the stroke. On a zero length subpath, the stroke consists of a square with its width equal to the stroke width, centered at the subpath's point.