Teach flutter to run from a relative path
Teach flutter to run from a relative path

Previously we were trying to run pub from the wrong working directory.

tvolkert/flutter,tvolkert/flutter,flutter/flutter,Hixie/flutter,aghassemi/flutter,cbracken/flutter,Hixie/flutter,cbracken/flutter,turnidge/flutter,Hixie/flutter,cbracken/flutter,turnidge/flutter,flutter/flutter,turnidge/flutter,flutter/flutter,tvolkert/flutter,aghassemi/flutter,cbracken/flutter,tvolkert/flutter,cbracken/flutter,flutter/flutter,Hixie/flutter,cbracken/flutter,tvolkert/flutter,Hixie/flutter,cbracken/flutter,tvolkert/flutter,tvolkert/flutter,Hixie/flutter,flutter/flutter,flutter/flutter,cbracken/flutter,cbracken/flutter,flutter/flutter,turnidge/flutter,cbracken/flutter,flutter/flutter,turnidge/flutter,flutter/flutter,Hixie/flutter,tvolkert/flutter,flutter/flutter,Hixie/flutter,Hixie/flutter,aghassemi/flutter,Hixie/flutter,tvolkert/flutter,aghassemi/flutter,tvolkert/flutter