MDL-54944 js: fix quoting of object properities coding style

Detected by http://eslint.org/docs/rules/quote-props

mod/lti/amd/src/tool_proxy.js

@@ -57,7 +57,7 @@ define(['core/ajax', 'core/notification'], function(ajax, notification) {
          * @param {Integer} id Tool proxy ID
          * @return {Promise} jQuery Deferred object
          */
-        delete: function(id) {
+        'delete': function(id) {
             var request = {
                 methodname: 'mod_lti_delete_tool_proxy',
                 args: {

mod/lti/amd/src/tool_type.js

@@ -106,7 +106,7 @@ define(['core/ajax', 'core/notification'], function(ajax, notification) {
          * @param {Integer} id Tool type ID
          * @return {Promise} jQuery Deferred object
          */
-        delete: function(id) {
+        'delete': function(id) {
             var request = {
                 methodname: 'mod_lti_delete_tool_type',
                 args: {

question/type/ddimageortext/yui/src/form/js/form.js

@@ -117,7 +117,7 @@ Y.extend(DDIMAGEORTEXT_FORM, M.qtype_ddimageortext.dd_base_class, {
         }
     },
     set_options_for_drag_item_selectors : function () {
-        var dragitemsoptions = {0: ''};
+        var dragitemsoptions = {'0': ''};
         for (var i = 0; i < this.form.get_form_value('noitems', []); i++) {
             var label = this.form.get_form_value('draglabel', [i]);
             var file = this.fp.file(this.form.to_name_with_index('dragitem', [i]));

question/type/ddmarker/yui/src/form/js/form.js

@@ -116,7 +116,7 @@ Y.extend(DDMARKER_FORM, M.qtype_ddmarker.dd_base_class, {
         }
     },
     set_options_for_drag_item_selectors : function () {
-        var dragitemsoptions = {0: ''};
+        var dragitemsoptions = {'0': ''};
         for (var i = 1; i <= this.form.get_form_value('noitems', []); i++) {
             var label = this.get_marker_text(i);
             if (label !== "") {