Remove jQuery and replace with XHR (#137)

.eslintignore

@@ -8,4 +8,3 @@ coverage/*
 # login-related files
 public/script.js
 public/login.html
-public/jquery-2.2.4.min.js

config/webpack.config.prod.js

@@ -350,4 +350,7 @@ module.exports = {
     net: 'empty',
     tls: 'empty',
   },
+  performance: {
+    hints: "warning",
+  },
 };

public/login.html

@@ -38,23 +38,20 @@ <h2>Custom</h2>
     <button type="submit">Submit</button>
   </form>
 </div>
-<script src="./jquery-2.2.4.min.js"></script>
 <script>
   function login(username, password) {
-    $.ajax({
-      type:"POST",
-      url:"%API_URL%/accounts/token/",
-      data: "username=" + username + "&password=" + password,
-      success: function(data) {
-        window.location.href = '%PUBLIC_URL%/tokenValidation?tmApiToken=' + data.token
-      },
-      error: function(){
-        alert('Request failed');
-      },
-      dataType: 'json',
-    });
+    // create XMLHttpRequest
+    var xhr = new XMLHttpRequest();
+    xhr.open("POST", "%API_URL%/accounts/token/");
+    xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
+    xhr.onreadystatechange = function() {
+      if (xhr.readyState === 4) {
+        window.location.href = '%PUBLIC_URL%/tokenValidation?tmApiToken=' + JSON.parse(xhr.response).token
+      }
+    };
 
-  };
+    xhr.send("username=" + username + "&password=" + password);
+  }
 
   function submitLogin() {
     login(document.getElementById('username').value, document.getElementById('password').value);