Did you set your secret and key for LinkedIn and Twitter in your settings.py?
Once that is done you may have to set the redirect urls with those providers.
I tested with google and had to fix my Google API Access settings.
I changed redirect urls to http://localhost:8000/complete/google-oauth2/
UPDATE: I am having issues with LinkedIn on oauth1 & 2. There doesnt appear to be a way to get the required API key into the request. I have attempted to hard code in the oauth1_auth.py of requests_oauthlib but with no success yet.
UPDATE 2: Twitter worked for me by making sure my twitter developer application settings had "Allow this application to Sign in with Twitter" checked and my consumer key and secret set in my settings.py like so:
# TWITTER
#
SOCIAL_AUTH_TWITTER_KEY = '<...>'
SOCIAL_AUTH_TWITTER_SECRET = '<.....>'