change node resolve param to allow cjs modules, prefer mjs

by changing "modulesOnly" to just "modules", rollup will look for
an mjs module by default, but accept and bundle cjs if not

Author: jescalan

src/index.js

@@ -195,7 +195,7 @@ function createConfig(options, entry, format) {
 					include: 'node_modules/**'
 				}),
 				useNodeResolve && nodeResolve({
-					modulesOnly: true,
+					module: true,
 					jsnext: true
 				}),
 				es3(),