Do not include sourcemap files in Service Worker shell

Fixes #534

test/apps/with-sourcemaps/rollup.config.js

@@ -0,0 +1,64 @@
+import resolve from 'rollup-plugin-node-resolve';
+import replace from 'rollup-plugin-replace';
+import svelte from 'rollup-plugin-svelte';
+
+const mode = process.env.NODE_ENV;
+const dev = mode === 'development';
+
+const config = require('../../../config/rollup.js');
+
+export default {
+	client: {
+		input: config.client.input(),
+		output: Object.assign({}, config.client.output(), { sourcemap: true }),
+		plugins: [
+			replace({
+				'process.browser': true,
+				'process.env.NODE_ENV': JSON.stringify(mode)
+			}),
+			svelte({
+				dev,
+				hydratable: true,
+				emitCss: true
+			}),
+			resolve()
+		],
+
+		// temporary, pending Rollup 1.0
+		experimentalCodeSplitting: true
+	},
+
+	server: {
+		input: config.server.input(),
+		output: config.server.output(),
+		plugins: [
+			replace({
+				'process.browser': false,
+				'process.env.NODE_ENV': JSON.stringify(mode)
+			}),
+			svelte({
+				generate: 'ssr',
+				dev
+			}),
+			resolve({
+				preferBuiltins: true
+			})
+		],
+		external: ['sirv', 'polka'],
+
+		// temporary, pending Rollup 1.0
+		experimentalCodeSplitting: true
+	},
+
+	serviceworker: {
+		input: config.serviceworker.input(),
+		output: config.serviceworker.output(),
+		plugins: [
+			resolve(),
+			replace({
+				'process.browser': true,
+				'process.env.NODE_ENV': JSON.stringify(mode)
+			})
+		]
+	}
+};