PLT-1465 Added password requirements (#3489)

* Added password requirements

* added tweaks

* fixed error code

* removed http.StatusNotAcceptable

api/admin.go

@@ -550,7 +550,8 @@ func adminResetPassword(c *Context, w http.ResponseWriter, r *http.Request) {
 	}
 
 	newPassword := props["new_password"]
-	if len(newPassword) < model.MIN_PASSWORD_LENGTH {
+	if err := utils.IsPasswordValid(newPassword); err != nil {
+		c.Err = err
 		c.SetInvalidParam("adminResetPassword", "new_password")
 		return
 	}