def authenticate(api_id, username, password)
      response = execute_command('auth', 'http',
        :api_id => api_id,
        :user => username,
        :password => password
      )
      parse_response(response)['OK']
    end
def authenticate(api_id, username, password)
      response = execute_command('auth', 'http',
        :api_id => api_id,
        :user => username,
        :password => password
      )
      parse_response(response)['OK']
    end
Creates a new API instance using the specified +auth options+.
 +auth_options+ is a hash containing either a :session_id or
 :username, :password and :api_key.

 Some API calls (authenticate, ping etc.) do not require any
 +auth_options+. +auth_options+ can be updated using the accessor methods.
 Authenticates using the specified credentials. Returns
 a session_id if successful which can be used in subsequent
 API calls.