(merge_request_approvals) fix inconsistency with parameter names (#395)

merge_request_approvals.go

@@ -70,12 +70,12 @@ type ApproveMergeRequestOptions struct {
 //
 // GitLab API docs:
 // https://docs.gitlab.com/ee/api/merge_request_approvals.html#approve-merge-request
-func (s *MergeRequestApprovalsService) ApproveMergeRequest(pid interface{}, mrID int, opt *ApproveMergeRequestOptions, options ...OptionFunc) (*MergeRequestApprovals, *Response, error) {
+func (s *MergeRequestApprovalsService) ApproveMergeRequest(pid interface{}, mr int, opt *ApproveMergeRequestOptions, options ...OptionFunc) (*MergeRequestApprovals, *Response, error) {
 	project, err := parseID(pid)
 	if err != nil {
 		return nil, nil, err
 	}
-	u := fmt.Sprintf("projects/%s/merge_requests/%d/approve", url.QueryEscape(project), mrID)
+	u := fmt.Sprintf("projects/%s/merge_requests/%d/approve", url.QueryEscape(project), mr)
 
 	req, err := s.client.NewRequest("GET", u, opt, options)
 	if err != nil {