Refactored goauth methods and other related methods

* set the goauth_token to None in the logout() method
	- might have solved the logout/logging in bug
* created temporary oauth and goauth variable in constructor
	- will help prevent bugs because methods are pass-by-reference
* changed the constructor login attempt to use the client from the config
* changed the appropriate goauth methods to use _issue_rest_request
	- ssl is no longer verified (probably will want to reimplement later)
* changed _issue_rest_request to be compatible with 'text/html' returned content-type
* renamed merged_tests directory to tests
* renamed MergedClient to GlobusOnlineRestClient
* added another sample called sample2
	- meant as a sanity check for goauth login