Kill sky_server by port instead of pid
Kill sky_server by port instead of pid

We seem to have trouble killing sky_server by its pid. Instead, lets try
killing it by looking up which process is listening on the sky_server port.

flutter/flutter,aghassemi/flutter,jason-simmons/flutter,flutter/flutter,flutter/flutter,tvolkert/flutter,cbracken/flutter,flutter/flutter,cbracken/flutter,tvolkert/flutter,turnidge/flutter,cbracken/flutter,Hixie/flutter,aghassemi/flutter,tvolkert/flutter,cbracken/flutter,Hixie/flutter,turnidge/flutter,cbracken/flutter,aghassemi/flutter,tvolkert/flutter,flutter/flutter,flutter/flutter,Hixie/flutter,tvolkert/flutter,Hixie/flutter,Hixie/flutter,turnidge/flutter,tvolkert/flutter,flutter/flutter,turnidge/flutter,cbracken/flutter,tvolkert/flutter,tvolkert/flutter,turnidge/flutter,Hixie/flutter,jason-simmons/flutter,flutter/flutter,cbracken/flutter,Hixie/flutter,cbracken/flutter,Hixie/flutter,tvolkert/flutter,tvolkert/flutter,jason-simmons/flutter,Hixie/flutter,cbracken/flutter,jason-simmons/flutter,flutter/flutter,cbracken/flutter,Hixie/flutter,flutter/flutter,aghassemi/flutter