Adding xero support
Update OAuth/ResourceOwner/GenericOAuth1ResourceOwner.php

Fix compatibility with OAuth 1.0 Server
Added support for FOSUserBundle 1.3 and 2.x
Extend tests for `GenericOAuth1ResourceOwner` & `LinkedinResourceOwnerTest`
Extend tests for `GenericOAuth2ResourceOwner` and extending classes
Extend tests for `SensioConnectResourceOwner` and fix recent change in uuid parsing
Update OAuth/ResourceOwner/GenericOAuth1ResourceOwner.php

Fix #186 & #187
Added support for Yahoo OAuth 1.0
Rebase & add tests to Yahoo resource owner
Update OAuth/ResourceOwner/AbstractResourceOwner.php

Always set `User-Agent` header.