Added Digital Ocean sponsor

Author: aryadas98

images/DO_Logo_Vertical_Blue.png

@@ -92,6 +92,7 @@
           <div class="nwoc-header-sponsors">
               <p>Sponsored By:</p>
               <a href="https://www.jetbrains.com/" target="_blank"><img src="images/jetbrains-variant-2-cropped.png"/></a>
+              <a href="https://www.digitalocean.com"/ target="_blank"><img src="images/DO_Logo_Vertical_White.png"/></a>
           </div>
         </div>
 
@@ -218,6 +219,7 @@ <h3>Register</h3>
 
           <h3>Sponsors</h3>
           <a href="https://www.jetbrains.com/" target="_blank"><img class="nwoc-current-sponsors" src="images/jetbrains-variant-1.png"/></a>
+          <a href="https://www.digitalocean.com" target="_blank"><img class="nwoc-current-sponsors" src="images/DO_Logo_Vertical_Blue.png"/></a>
 
           <h3>Previous projects</h3>
           <p>NWoC 2017 saw a huge participation of more than 200 students from all across the country. 

images/DO_Logo_Vertical_White.png

@@ -148,7 +148,9 @@ h2,h3 {
 }
 
 .nwoc-header-sponsors img {
-  width: 70px;
+  height: 70px;
+  padding-right: 10px;
+  padding-left: 10px;
 }
 
 .nwoc-content {
@@ -216,6 +218,8 @@ h2,h3 {
 
 .nwoc-current-sponsors {
   height: 160px;
+  margin-right: 30px;
+  margin-bottom: 30px;
 }
 
 .nwoc-repo-card {
@@ -299,7 +303,7 @@ h2,h3 {
   }
 
   .nwoc-header-sponsors img {
-    width: 60px;
+    height: 60px;
   }
 
   .nwoc-header-sponsors p {