Removing BB dependency in another file

#14940
another file that was using BB has been freed of the dependency. Both the files are core/frontend/meta/get-meta.js is dependent on image-dimensions.js in the same folder.
BB was removed from image-dimensions in my previous commit

ghost/core/core/frontend/meta/get-meta.js

@@ -1,4 +1,3 @@
-const Promise = require('bluebird');
 const settingsCache = require('../../shared/settings-cache');
 const urlUtils = require('../../shared/url-utils');
 const logging = require('@tryghost/logging');
@@ -81,7 +80,7 @@ function getMetaData(data, root) {
     }
 
     // @TODO: wrap this in a utility function
-    return Promise.props(getImageDimensions(metaData)).then(function () {
+    return getImageDimensions(metaData).then(function () {
         metaData.structuredData = getStructuredData(metaData);
         metaData.schema = getSchema(metaData, data);