Dr. Chaos released!

[planetis]

v0.1.5 of Dr. Chaos released! This update includes a performance boost for Nim 
devel, various bugs fixed and a new feature, overloaded `default` can be used. 
As well as two new examples, fuzzing a 
[matrix](https://github.com/status-im/nim-drchaos/blob/master/examples/fuzz_matrix.nim)
 and [HTML 
tree](https://github.com/status-im/nim-drchaos/blob/master/examples/fuzz_html.nim)