make the standalone build umd-compliant

fixes #2191

CHANGELOG.md

@@ -7,7 +7,6 @@ _The format is based on [Keep a Changelog](http://keepachangelog.com/) and this
 ## Unreleased
 
 - Performance optimization for fully static (no function interpolation) styled-components by avoiding using `ThemeConsumer` since it isn't necessary, by [@mxstbr](https://github.com/mxstbr) (see [#2166](https://github.com/styled-components/styled-components/pull/2166))
-- Allow disabling "speedy" mode via global `SC_DISABLE_SPEEDY` variable, by [@devrelm](https://github.com/devrelm) (see [#2185](https://github.com/styled-components/styled-components/pull/2185))
 
 - Allow disabling "speedy" mode via global `SC_DISABLE_SPEEDY` variable, by [@devrelm](https://github.com/devrelm) (see [#2185](https://github.com/styled-components/styled-components/pull/2185))
 
@@ -40,6 +39,8 @@ _The format is based on [Keep a Changelog](http://keepachangelog.com/) and this
 
   Support for this will be removed in styled-components v5. The primary impetus behind this change is to eliminate confusion around basic functions vs styled-components vs React components provided as values in the object-form attrs constructor, each of which has different handling behaviors. The single outer function to receive the props and then return a props object is conceptually simpler.
 
+- The standalone CDN build is now UMD-compliant and can be used with RequireJS, etc.
+
 ## [v4.0.3] - 2018-10-30
 
 - Interpolating a styled component into a string now returns the static component selector (emotion cross-compat)

rollup.config.js

@@ -75,8 +75,7 @@ const standaloneBaseConfig = {
   input: './src/index-standalone.js',
   output: {
     file: 'dist/styled-components.js',
-    format: 'iife',
-    footer: ';window.styled = styled;',
+    format: 'umd',
     globals,
     name: 'styled',
     sourcemap: true,