fix(tests): windows issues

util.go - windows fails trying to open socket on host 0.0.0.0; replaced
with localhost(127.0.0.1)
https://code.google.com/p/go/issues/detail?id=6290

http://msdn.microsoft.com/en-us/library/windows/desktop/ms740668(v=vs.85).aspx
simple_snapshot_test.go - panic when err != nil