fix(v2): ensure migrate script validates Casper correctly

refs #759
- if your active theme is "casper", we have to validate the casper theme from the v2 folder
- otherwise we will validate casper from Ghost v1 with GScan v2

Author: kirrg001

lib/tasks/major-update/data.js

@@ -24,7 +24,7 @@ module.exports = function getData(options = {}) {
 
     const connection = knex(Object.assign({useNullAsDefault: true}, options.database));
 
-    const themeFolder = path.resolve(options.dir, 'content', 'themes');
+    let themeFolder = path.resolve(options.dir, 'content', 'themes');
     let gscanReport;
 
     return connection.raw('SELECT * FROM settings WHERE `key`="active_theme";')
@@ -37,6 +37,11 @@ module.exports = function getData(options = {}) {
                 activeTheme = response[0].value;
             }
 
+            // CASE: use casper from v2 folder, otherwise we are validating the old casper
+            if (activeTheme === 'casper') {
+                themeFolder = path.resolve(options.dir, options.version, 'content', 'themes');
+            }
+
             return gscan.check(path.resolve(themeFolder, activeTheme));
         })
         .then((report) => {