Fixed incorrect usage of id field in sdk.variable and used key

lib/schemaUtils.js

@@ -418,7 +418,7 @@ module.exports = {
       _.forOwn(serverVariables, (value, key) => {
         let description = this.getParameterDescription(value);
         variables.push(new sdk.Variable({
-          id: key,
+          key: key,
           value: value.default || '',
           description: description
         }));
@@ -426,7 +426,7 @@ module.exports = {
     }
     if (keyName) {
       variables.push(new sdk.Variable({
-        id: keyName,
+        key: keyName,
         value: serverUrl,
         type: 'string'
       }));
@@ -2128,7 +2128,7 @@ module.exports = {
           convertedPathVar = _.get(this.convertParamsWithStyle(element, fakedData, PARAMETER_SOURCE.REQUEST,
             components, schemaCache, options), '[0]', {});
 
-        variableStore[element.name] = _.assign(convertedPathVar, { id: element.name, type: 'collection' });
+        variableStore[element.name] = _.assign(convertedPathVar, { key: element.name, type: 'collection' });
       }
     });
     // accounting for the overriding of the root level and path level servers object if present at the operation level
@@ -2159,7 +2159,7 @@ module.exports = {
         sanitizeResult.collectionVars.forEach((element) => {
           if (!variableStore[element.name]) {
             variableStore[element.name] = {
-              id: element.name,
+              key: element.name,
               value: element.value || '',
               description: element.description,
               type: 'collection'