def add_member_to(group_id, document)
      response = make_request(:post, group + "/#{group_id}/member", body: document, headers: {'content-type' => 'application/atom+xml'})
      create_doc(response.body)
    end
def add_member_to(group_id, document)
      response = make_request(:post, group + "/#{group_id}/member", body: document, headers: {'content-type' => 'application/atom+xml'})
      create_doc(response.body)
    end
add_member_to adds a member to a group in the domain.
 It takes a group_id and a GoogleApps::Atom::GroupMember
 document as arguments.

 add_member_to 'test', document

 add_member_to returns the response received from Google.