Added Icons in Navbar

Author: mohak852

src/components/Navbar/Navbar.css

@@ -31,32 +31,11 @@
     background-color: #4CAF50;
     color: white;
 }
-.slack{
-    display: inline-block;
-    vertical-align:middle;
-    margin-top: 10px;
-    width: 60px;
-    height: 40px;
-}
-.youtube{
-    vertical-align:middle;
-    margin-top: 10px;
-    width: 70px;
-    height: 50px;
-    display: inline-block;
-}
-.github{
-    margin-top: 10px;
-    vertical-align:middle;
-    width: 60px;
-    height: 50px;
-    display: inline-block;
-}
-.twitter{
+
+.logo{
     margin-top: 10px;
     width: 60px;
     vertical-align:middle;
     height: 50px;
-    fill: white;
     display: inline-block;
-} 
+}

src/components/Navbar/Navbar.jsx

@@ -9,19 +9,19 @@ class Navbar extends Component {
         return (
             <div className="topnav">
                 <a href="https://join.slack.com/t/firstcontributors/shared_invite/enQtNjkxNzQwNzA2MTMwLTVhMWJjNjg2ODRlNWZhNjIzYjgwNDIyZWYwZjhjYTQ4OTBjMWM0MmFhZDUxNzBiYzczMGNiYzcxNjkzZDZlMDM"  target="_blank" rel="noopener noreferrer">
-                <img src={slack} className="slack"/>
+                <img src={slack} className="logo"/>
                 <span>Slack</span>
                 </a>
                 <a href="https://www.youtube.com/channel/UCMXNFxCvyH5LhUwEcmY8qGQ" target="_blank" rel="noopener noreferrer">
-                <img  src={youtube} className="youtube"/>
+                <img  src={youtube} className="logo"/>
                 <span>Youtube</span>    
                 </a>
                 <a href="https://twitter.com/1stContribution" target="_blank" rel="noopener noreferrer">
-                <img   src={twitter} className="twitter"/>
+                <img   src={twitter} className="logo"/>
                 <span>Twitter</span>
                 </a>
                 <a href="https://github.com/firstcontributions/first-contributions" target="_blank" rel="noopener noreferrer">
-                <img  src={github} className="github"/>
+                <img  src={github} className="logo"/>
                 Github
                 </a>
             </div>