func (s *RepositoriesService) RawBlobContent(pid interface{}, sha string, options ...OptionFunc) ([]byte, *Response, error) {
	project, err := parseID(pid)
	if err != nil {
		return nil, nil, err
	}
	u := fmt.Sprintf("projects/%s/repository/blobs/%s/raw", url.QueryEscape(project), sha)
	req, err := s.client.NewRequest("GET", u, nil, options)
	if err != nil {
		return nil, nil, err
	}
	var b bytes.Buffer
	resp, err := s.client.Do(req, &b)
	if err != nil {
		return nil, resp, err
	}
	return b.Bytes(), resp, err
}
RawBlobContent gets the raw file contents for a blob by blob SHA.

GitLab API docs:
https://docs.gitlab.com/ce/api/repositories.html#raw-blob-content
package gitlab
import (
	"bytes"
	"fmt"
	"net/url"
)
type RepositoriesService struct {
	client *Client
}
type TreeNode struct {
	ID   string `json:"id"`
	Name string `json:"name"`
	Type string `json:"type"`
	Path string `json:"path"`
	Mode string `json:"mode"`
}
func (t TreeNode) String() string {
	return Stringify(t)
}
type ListTreeOptions struct {
	Path      *string `url:"path,omitempty" json:"path,omitempty"`
	Ref       *string `url:"ref,omitempty" json:"ref,omitempty"`
	Recursive *bool   `url:"recursive,omitempty" json:"recursive,omitempty"`
}
func (s *RepositoriesService) ListTree(pid interface{}, opt *ListTreeOptions, options ...OptionFunc) ([]*TreeNode, *Response, error) {
	project, err := parseID(pid)
	if err != nil {
		return nil, nil, err
	}
	u := fmt.Sprintf("projects/%s/repository/tree", url.QueryEscape(project))
	req, err := s.client.NewRequest("GET", u, opt, options)
	if err != nil {
		return nil, nil, err
	}
	var t []*TreeNode
	resp, err := s.client.Do(req, &t)
	if err != nil {
		return nil, resp, err
	}
	return t, resp, err
}
func (s *RepositoriesService) RawFileContent(pid interface{}, sha string, options ...OptionFunc) ([]byte, *Response, error) {
	project, err := parseID(pid)
	if err != nil {
		return nil, nil, err
	}
	u := fmt.Sprintf("projects/%s/repository/blobs/%s", url.QueryEscape(project), sha)
	req, err := s.client.NewRequest("GET", u, nil, options)
	if err != nil {
		return nil, nil, err
	}
	var b bytes.Buffer
	resp, err := s.client.Do(req, &b)
	if err != nil {
		return nil, resp, err
	}
	return b.Bytes(), resp, err
}