add badge for travis and coverall
fix Http-Authorization in header. fix on logger
password credential works well now
add test case for password credential
increase test coverage for client part
coverage should run in DEBUG mode
mark no cover for get etree
add provider on api docs
implement user on credentical grant type. #6
fix on test cases
add test case for client credential. #6
Implemented request token validation and handler. Added tests for request token validator and handler.