Changes to the Oauth1Client.getAccessToken method

• The Oauth1ClientConfig doesn't accept the oauthToken and oauthTokenSecret properties anymore.

• The getAccessToken method instead accepts an object with token and secret values. Same as the values you defined in the config earlier

• Finally removed the client.child method that uses to create a child instance of the client

• refactor: accept "requestToken.token" and "requestToken.secret" at the time of generating access token 9bcc161

v1.1.1...v2.0.0