Service for storing and retrieving user tokens.
http://lakm.us/logit/2013/01/https-server-client-certificate-pair-1-generate-openssl/
curl -vvv https://localhost:7878/accounts/user1/refresh_token --cert fixtures/client/certs/client1.crt --key fixtures/client/keys/client1.key --cacert fixtures/ca/myCA.crtcurl -vvv https://localhost:7878/accounts/user1/access_token --cert fixtures/client/certs/client1.crt --key fixtures/client/keys/client1.key --cacert fixtures/ca/myCA.crt