fixed bug with resolve and absolute aliases on windows

[hzrd149]

this pull request is to fix the bug that arises when you use absolute paths in aliases on Windows

for example, if you do this

alias({
  resolve: ['.jsx', '.js'],
  lib: path.resolve(__dirname, './lib/')
})

and then if you import lib/some/file it wont resolve to /absolute/path/project/lib/some/file.jsx, since the lib alias has the drive letter in it, and the code here dose not test for a drive letters

to fix this, i made it strip out the drive letter once it has replaced the alias in the importeeId path

[Rich-Harris]

Thanks for the PR. I'm hoping that this is similar to #22. If you get a chance to try 1.4.0 could you see if the issue is resolved please?

[hzrd149]

@Rich-Harris looks like that fixed it 👍

thanks for the fix