fix errors

src/Board.js

@@ -155,7 +155,6 @@ class Board extends React.Component {
                         <img
                           className= "tabset-button"
                           src="images/icons/settings.svg"
-                          className= "tabset-button"
                           alt="settings"
                           key="settings"
                           onClick={modeToggle("settings").bind(node)}

src/Menu/index.js

 import React from "react";
 
-import SideNav, { Toggle, Nav, NavItem, NavIcon, NavText } from '@trendmicro/react-sidenav';
+import SideNav, { NavItem, NavIcon, NavText } from '@trendmicro/react-sidenav';
 import './Menu.css'
 
 
@@ -26,11 +26,12 @@ export function Menu(props) {
 
         <NavItem eventKey="demo">
           <NavIcon>
-            <a>
+            {/* <a href="#"> */}
               <img className="menu-button"
                 src={window.location.origin + "/images/icons/dashboard-grey.svg"}
+                alt="Demo mode"
               />
-            </a>
+            {/* </a> */}
           </NavIcon>
           <NavText>
             Demo
@@ -47,11 +48,12 @@ export function Menu(props) {
 
         <NavItem eventKey="memory">
           <NavIcon>
-            <a>
+            {/* <a> */}
               <img className="menu-button"
                 src={window.location.origin + "/images/icons/memory-grey.svg"}
+                alt="memory dashboard"
               />
-            </a>
+            {/* </a> */}
           </NavIcon>
           <NavText>
             Memory
@@ -60,11 +62,12 @@ export function Menu(props) {
 
         <NavItem eventKey="traces">
           <NavIcon>
-            <a>
+            {/* <a> */}
               <img className="menu-button"
                 src={window.location.origin + "/images/icons/trace-grey.svg"}
+                alt="trace dashboard"
               />
-            </a>
+            {/* </a> */}
           </NavIcon>
           <NavText>
             Traces
@@ -73,11 +76,12 @@ export function Menu(props) {
 
         <NavItem eventKey="mental-states">
           <NavIcon>
-            <a>
+            {/* <a> */}
               <img className="menu-button"
                 src={window.location.origin + "/images/icons/mood-grey.svg"}
+                alt="mood dashboard"
               />
-            </a>
+            {/* </a> */}
           </NavIcon>
           <NavText>
             Mental states
@@ -86,11 +90,12 @@ export function Menu(props) {
 
         <NavItem eventKey="decision-making">
           <NavIcon>
-            <a>
+            {/* <a> */}
               <img className="menu-button"
                 src={window.location.origin + "/images/icons/choice-grey.svg"}
+                alt="choice dashboard"
               />
-            </a>
+            {/* </a> */}
           </NavIcon>
           <NavText>
             Decision making
@@ -103,11 +108,12 @@ export function Menu(props) {
 
         <NavItem eventKey="video">
           <NavIcon>
-            <a>
+            {/* <a> */}
               <img className="menu-button"
                 src={window.location.origin + "/images/icons/video-grey.svg"}
+                alt="video dashboard"
               />
-            </a>
+            {/* </a> */}
           </NavIcon>
           <NavText>
             Video
@@ -116,11 +122,12 @@ export function Menu(props) {
 
         <NavItem eventKey="audio">
           <NavIcon>
-            <a>
+            {/* <a> */}
               <img className="menu-button"
                 src={window.location.origin + "/images/icons/microphone-grey.svg"}
+                alt="microphone dashboard"
               />
-            </a>
+            {/* </a> */}
           </NavIcon>
           <NavText>
             Audio
@@ -129,11 +136,12 @@ export function Menu(props) {
 
         <NavItem eventKey="sensory">
           <NavIcon>
-            <a>
+            {/* <a> */}
               <img className="menu-button"
                 src={window.location.origin + "/images/icons/fingerprint-grey.svg"}
+                alt="sensory dashboard"
               />
-            </a>
+            {/* </a> */}
           </NavIcon>
           <NavText>
             Sensory
@@ -143,14 +151,16 @@ export function Menu(props) {
         <a href="more.html">
           <img className="footer menu-button about-button"
             src={window.location.origin + "/images/icons/about.svg"}
+            alt="about this dashboard"
           />
         </a>
 
-        <a>
+        {/* <a> */}
           <img className="footer menu-button lock-button"
             src={window.location.origin + "/images/icons/lock_closed-grey.svg"}
+            alt="lock/unlock the dashboard"
           />
-        </a>
+        {/* </a> */}
       </SideNav.Nav>
     </SideNav>
   )