Export wrap as es2015 instead of commonjs

packages/apollo-boost/rollup-bundle.config.js

@@ -17,6 +17,7 @@ const globals = {
   'fast-json-stable-stringify': 'stringify',
   'graphql-tag': 'gql',
   'apollo-utilities': 'apolloUtilities',
+  optimism: 'optimism',
 };
 
 export default {

packages/apollo-cache-inmemory/rollup.config.js

@@ -3,6 +3,8 @@ import build, { globals } from '../../config/rollup.config';
 const globalsOverride = {
   ...globals,
   'graphql/language/printer': 'print',
+  optimism: 'optimism',
+  'graphql/language/visitor': 'visitor',
 };
 
 export default build('apollo.cache.inmemory', {

packages/apollo-cache-inmemory/src/declarations.d.ts

@@ -0,0 +1,6 @@
+declare module 'optimism' {
+  export function wrap<T>(
+    originalFunction: T,
+    options?: OptimisticWrapOptions,
+  ): OptimisticWrapperFunction<T>;
+}

packages/apollo-cache-inmemory/src/optimism.ts

@@ -1,5 +1,3 @@
-declare function require(id: string): any;
-
 export type OptimisticWrapperFunction<
   T = (...args: any[]) => any
 > = T & {
@@ -14,16 +12,7 @@ export type OptimisticWrapOptions = {
   makeCacheKey?(...args: any[]): any;
 };
 
-const {
-  wrap,
-}: {
-  wrap<T>(
-    originalFunction: T,
-    options?: OptimisticWrapOptions,
-  ): OptimisticWrapperFunction<T>;
-} = require('optimism'); // tslint:disable-line
-
-export { wrap };
+export { wrap } from 'optimism';
 
 export class CacheKeyNode<KeyType = object> {
   private children: Map<any, CacheKeyNode<KeyType>> | null = null;