Rename welcome to index according to vue files

frontend/test/e2e/admin.test.js

 module.exports = {
   'Login' : function (browser) {
-    const welcome = browser.page.welcome();
-    const navbar = welcome.section.navbar;
+    const index = browser.page.index();
+    const navbar = index.section.navbar;
     const login = browser.page.login()
 
-    welcome
+    index
       .navigate()
       .waitForElementVisible('@loginButton')
       .click("@loginButton")
@@ -17,7 +17,7 @@ module.exports = {
       .setValue('input[name=password]', browser.globals.adminPassword)
       .click('input[name=submit]')
 
-    welcome
+    index
       .waitForElementVisible('@logoutButton')
 
     navbar

frontend/test/e2e/guest.test.js

 
 module.exports = {
   'Welcome screen' : function (browser) {
-    const welcome = browser.page.welcome();
-    const navbar = welcome.section.navbar;
-    welcome.navigate()
+    const index = browser.page.index();
+    const navbar = index.section.navbar;
+    index.navigate()
       .waitForElementVisible('body')
       .assert.containsText('@banner', 'Welcome to OpenAppStack')
 
@@ -14,8 +14,8 @@ module.exports = {
   },
   'Login screen' : function (browser) {
     const login = browser.page.login()
-    const welcome = browser.page.welcome();
-    welcome.navigate()
+    const index = browser.page.index();
+    index.navigate()
       .waitForElementVisible('body')
       .click("@loginButton")
     login

frontend/test/e2e/user.test.js

 module.exports = {
   'Login' : function (browser) {
-    const welcome = browser.page.welcome();
-    const navbar = welcome.section.navbar;
+    const index = browser.page.index();
+    const navbar = index.section.navbar;
     const login = browser.page.login()
-    welcome.navigate()
+    index.navigate()
       .waitForElementVisible('@loginButton')
       .click("@loginButton")
     login
@@ -14,7 +14,7 @@ module.exports = {
       .setValue('input[name=password]', browser.globals.userPassword)
       .click('input[name=submit]')
 
-    welcome
+    index
       .waitForElementVisible('@logoutButton')
       .assert.containsText('@logoutButton', 'Logout')