Merge pull request #61 from raoulmillais/3-legged-signing

Add support for 3-legged signing
0.26.0
Allow passing no parameters to oauth.sign

- Fixes issue #62
Account for new stub port in int tests
0.26.1
Assume xml content type if none defined
Fix readme slash typo
Authorise oauth test 3-legged without user input
Remove redundant previews tests
Implement basket example correctly
Up example test timeout, show output & run all
Rename create user example & refactor to waterfall
Use https for retrieving request token
Implement put and user account management