Setup appveyor

Here we have an appveyor.yml file that woks with nodejs.
Tests needed to be updated, appveyor is much slower than travis in all way possible.

btw, I ve noticed pouchdb is not compatible nodejs@0.11.
well saw. Maybe when i removed this line the output log will appear.

The thing is i can t see which tests are failing, so i believe this was just bug-ing.
Or a problem of return code. Not sure yet.

The real difficulty being that i don t run windows myself to eventually test those things quickly, do you ?