OAuthRemoteApp now checks to see if base_url is a valid http url

[Taar]

It turns out that urlparse.urljoin can't join urls without a schema. So i've added a check to OAuthRemoteApp to check base_url to see if it is in fact has a valid http schema.

[lepture]

format is not available in Python 2.6

[lepture]

>>> '{}'.format('foo')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: zero length field name in format

It will always be ValueError.

[lepture]

@Taar Sorry for the delay. Actually, I don't think that we need to verify the base url, it is the developer's job to make sure that it works properly.

[Taar]

@lepture It's not really for validation but rather informing the developer that they've provided a bad url. urlparse.urljoin won't return the expected url if the base_url doesn't have a http scheme. It throws an error saying it can't resolve the url. I just don't think the stack trance is intuitive enough.

[lepture]

@Taar I'd like to add a note on documentation instead of adding the code. Still, I think the developer should make sure himself.

[Taar]

@lepture Having something in the documentation would definitely help. I'll look into adding that in.