func (s *UsersService) ListSSHKeysForUser(user int, opt *ListSSHKeysForUserOptions, options ...OptionFunc) ([]*SSHKey, *Response, error) {
	u := fmt.Sprintf("users/%d/keys", user)
	req, err := s.client.NewRequest("GET", u, opt, options)
	if err != nil {
		return nil, nil, err
	}
	var k []*SSHKey
	resp, err := s.client.Do(req, &k)
	if err != nil {
		return nil, resp, err
	}
	return k, resp, err
}
ListSSHKeysForUser gets a list of a specified user's SSH keys. Available
only for admin

GitLab API docs:
https://docs.gitlab.com/ce/api/users.html#list-ssh-keys-for-user
package gitlab
import (
	"errors"
	"fmt"
	"time"
)
var (
	ErrUserBlockPrevented   = errors.New("Cannot block a user that is already blocked by LDAP synchronization")
	ErrUserNotFound         = errors.New("User does not exist")
	ErrUserUnblockPrevented = errors.New("Cannot unblock a user that is blocked by LDAP synchronization")
)
type UsersService struct {
	client *Client
}
type User struct {
	ID                        int                `json:"id"`
	Username                  string             `json:"username"`
	Email                     string             `json:"email"`
	Name                      string             `json:"name"`
	State                     string             `json:"state"`
	CreatedAt                 *time.Time         `json:"created_at"`
	Bio                       string             `json:"bio"`
	Location                  string             `json:"location"`
	PublicEmail               string             `json:"public_email"`
	Skype                     string             `json:"skype"`
	Linkedin                  string             `json:"linkedin"`
	Twitter                   string             `json:"twitter"`
	WebsiteURL                string             `json:"website_url"`
	Organization              string             `json:"organization"`
	ExternUID                 string             `json:"extern_uid"`
	Provider                  string             `json:"provider"`
	ThemeID                   int                `json:"theme_id"`
	LastActivityOn            *ISOTime           `json:"last_activity_on"`
	ColorSchemeID             int                `json:"color_scheme_id"`
	IsAdmin                   bool               `json:"is_admin"`
	AvatarURL                 string             `json:"avatar_url"`
	CanCreateGroup            bool               `json:"can_create_group"`
	CanCreateProject          bool               `json:"can_create_project"`
	ProjectsLimit             int                `json:"projects_limit"`
	CurrentSignInAt           *time.Time         `json:"current_sign_in_at"`
	LastSignInAt              *time.Time         `json:"last_sign_in_at"`
	ConfirmedAt               *time.Time         `json:"confirmed_at"`
	TwoFactorEnabled          bool               `json:"two_factor_enabled"`
	Identities                []*UserIdentity    `json:"identities"`
	External                  bool               `json:"external"`
	PrivateProfile            bool               `json:"private_profile"`
	SharedRunnersMinutesLimit int                `json:"shared_runners_minutes_limit"`
	CustomAttributes          []*CustomAttribute `json:"custom_attributes"`
}
type UserIdentity struct {
	Provider  string `json:"provider"`
	ExternUID string `json:"extern_uid"`
}
type ListUsersOptions struct {
	ListOptions
	Active  *bool `url:"active,omitempty" json:"active,omitempty"`
	Blocked *bool `url:"blocked,omitempty" json:"blocked,omitempty"`
	Search               *string    `url:"search,omitempty" json:"search,omitempty"`
	Username             *string    `url:"username,omitempty" json:"username,omitempty"`
	ExternalUID          *string    `url:"extern_uid,omitempty" json:"extern_uid,omitempty"`
	Provider             *string    `url:"provider,omitempty" json:"provider,omitempty"`
	CreatedBefore        *time.Time `url:"created_before,omitempty" json:"created_before,omitempty"`
	CreatedAfter         *time.Time `url:"created_after,omitempty" json:"created_after,omitempty"`
	OrderBy              *string    `url:"order_by,omitempty" json:"order_by,omitempty"`
	Sort                 *string    `url:"sort,omitempty" json:"sort,omitempty"`
	WithCustomAttributes *bool      `url:"with_custom_attributes,omitempty" json:"with_custom_attributes,omitempty"`
}
func (s *UsersService) ListUsers(opt *ListUsersOptions, options ...OptionFunc) ([]*User, *Response, error) {
	req, err := s.client.NewRequest("GET", "users", opt, options)
	if err != nil {
		return nil, nil, err
	}
	var usr []*User
	resp, err := s.client.Do(req, &usr)
	if err != nil {
		return nil, resp, err
	}
	return usr, resp, err
}
func (s *UsersService) GetUser(user int, options ...OptionFunc) (*User, *Response, error) {
	u := fmt.Sprintf("users/%d", user)
	req, err := s.client.NewRequest("GET", u, nil, options)
	if err != nil {
		return nil, nil, err
	}
	usr := new(User)
	resp, err := s.client.Do(req, usr)
	if err != nil {
		return nil, resp, err
	}
	return usr, resp, err
}
type CreateUserOptions struct {
	Email            *string `url:"email,omitempty" json:"email,omitempty"`
	Password         *string `url:"password,omitempty" json:"password,omitempty"`
	ResetPassword    *bool   `url:"reset_password,omitempty" json:"reset_password,omitempty"`
	Username         *string `url:"username,omitempty" json:"username,omitempty"`
	Name             *string `url:"name,omitempty" json:"name,omitempty"`
	Skype            *string `url:"skype,omitempty" json:"skype,omitempty"`
	Linkedin         *string `url:"linkedin,omitempty" json:"linkedin,omitempty"`
	Twitter          *string `url:"twitter,omitempty" json:"twitter,omitempty"`
	WebsiteURL       *string `url:"website_url,omitempty" json:"website_url,omitempty"`
	Organization     *string `url:"organization,omitempty" json:"organization,omitempty"`
	ProjectsLimit    *int    `url:"projects_limit,omitempty" json:"projects_limit,omitempty"`
	ExternUID        *string `url:"extern_uid,omitempty" json:"extern_uid,omitempty"`
	Provider         *string `url:"provider,omitempty" json:"provider,omitempty"`
	Bio              *string `url:"bio,omitempty" json:"bio,omitempty"`
	Location         *string `url:"location,omitempty" json:"location,omitempty"`
	Admin            *bool   `url:"admin,omitempty" json:"admin,omitempty"`
	CanCreateGroup   *bool   `url:"can_create_group,omitempty" json:"can_create_group,omitempty"`
	SkipConfirmation *bool   `url:"skip_confirmation,omitempty" json:"skip_confirmation,omitempty"`
	External         *bool   `url:"external,omitempty" json:"external,omitempty"`
}
func (s *UsersService) CreateUser(opt *CreateUserOptions, options ...OptionFunc) (*User, *Response, error) {
	req, err := s.client.NewRequest("POST", "users", opt, options)
	if err != nil {
		return nil, nil, err
	}
	usr := new(User)
	resp, err := s.client.Do(req, usr)
	if err != nil {
		return nil, resp, err
	}
	return usr, resp, err
}
type ModifyUserOptions struct {
	Email              *string `url:"email,omitempty" json:"email,omitempty"`
	Password           *string `url:"password,omitempty" json:"password,omitempty"`
	Username           *string `url:"username,omitempty" json:"username,omitempty"`
	Name               *string `url:"name,omitempty" json:"name,omitempty"`
	Skype              *string `url:"skype,omitempty" json:"skype,omitempty"`
	Linkedin           *string `url:"linkedin,omitempty" json:"linkedin,omitempty"`
	Twitter            *string `url:"twitter,omitempty" json:"twitter,omitempty"`
	WebsiteURL         *string `url:"website_url,omitempty" json:"website_url,omitempty"`
	Organization       *string `url:"organization,omitempty" json:"organization,omitempty"`
	ProjectsLimit      *int    `url:"projects_limit,omitempty" json:"projects_limit,omitempty"`
	ExternUID          *string `url:"extern_uid,omitempty" json:"extern_uid,omitempty"`
	Provider           *string `url:"provider,omitempty" json:"provider,omitempty"`
	Bio                *string `url:"bio,omitempty" json:"bio,omitempty"`
	Location           *string `url:"location,omitempty" json:"location,omitempty"`
	Admin              *bool   `url:"admin,omitempty" json:"admin,omitempty"`
	CanCreateGroup     *bool   `url:"can_create_group,omitempty" json:"can_create_group,omitempty"`
	SkipReconfirmation *bool   `url:"skip_reconfirmation,omitempty" json:"skip_reconfirmation,omitempty"`
	External           *bool   `url:"external,omitempty" json:"external,omitempty"`
}
func (s *UsersService) ModifyUser(user int, opt *ModifyUserOptions, options ...OptionFunc) (*User, *Response, error) {
	u := fmt.Sprintf("users/%d", user)
	req, err := s.client.NewRequest("PUT", u, opt, options)
	if err != nil {
		return nil, nil, err
	}
	usr := new(User)
	resp, err := s.client.Do(req, usr)
	if err != nil {
		return nil, resp, err
	}
	return usr, resp, err
}
func (s *UsersService) DeleteUser(user int, options ...OptionFunc) (*Response, error) {
	u := fmt.Sprintf("users/%d", user)
	req, err := s.client.NewRequest("DELETE", u, nil, options)
	if err != nil {
		return nil, err
	}
	return s.client.Do(req, nil)
}
func (s *UsersService) CurrentUser(options ...OptionFunc) (*User, *Response, error) {
	req, err := s.client.NewRequest("GET", "user", nil, options)
	if err != nil {
		return nil, nil, err
	}
	usr := new(User)
	resp, err := s.client.Do(req, usr)
	if err != nil {
		return nil, resp, err
	}
	return usr, resp, err
}
type SSHKey struct {
	ID        int        `json:"id"`
	Title     string     `json:"title"`
	Key       string     `json:"key"`
	CreatedAt *time.Time `json:"created_at"`
}
func (s *UsersService) ListSSHKeys(options ...OptionFunc) ([]*SSHKey, *Response, error) {
	req, err := s.client.NewRequest("GET", "user/keys", nil, options)
	if err != nil {
		return nil, nil, err
	}
	var k []*SSHKey
	resp, err := s.client.Do(req, &k)
	if err != nil {
		return nil, resp, err
	}
	return k, resp, err
}
type ListSSHKeysForUserOptions ListOptions