Remove support for 2.4 & 2.8

Author: rondale-sc

config/ember-try.js

@@ -1,38 +1,6 @@
 /* eslint-env node */
 module.exports = {
   scenarios: [
-    {
-      name: 'ember-lts-2.4',
-      bower: {
-        dependencies: {
-          'ember': 'components/ember#lts-2-4'
-        },
-        resolutions: {
-          'ember': 'lts-2-4'
-        }
-      },
-      npm: {
-        devDependencies: {
-          'ember-source': null
-        }
-      }
-    },
-    {
-      name: 'ember-lts-2.8',
-      bower: {
-        dependencies: {
-          'ember': 'components/ember#lts-2-8'
-        },
-        resolutions: {
-          'ember': 'lts-2-8'
-        }
-      },
-      npm: {
-        devDependencies: {
-          'ember-source': null
-        }
-      }
-    },
     {
       name: 'ember-release',
       bower: {