doesnt build on ubuntu 16.04 LTS

```
> src/build.sh 
gcc: error: unrecognized command line option ‘-W1,-soname,yamlwrap.so.1’
If you're running locally you may need to add this dir to LD_LIBRARY_PATH
  to do that, run: export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:/home/martin/.workspace/p6/perl6-libyaml"

```