added input option, removed deprecated entry

"entry" is deprecated. "input" property should be used to select entry file:
https://github.com/rollup/rollup/blob/master/src/rollup/index.js#L71-L76

Also, `string[]` cannot be used for entry/input. Using array results in error.

types/rollup/index.d.ts

@@ -86,7 +86,7 @@ export interface Bundle {
 
 export interface Options {
 	/** The bundle's entry point (e.g. your `main.js` or `app.js` or `index.js`) */
-	entry: string | string[]
+	input: string
 	/** A previous bundle. Use it to speed up subsequent bundles :) */
 	cache?: Bundle
 	/**

types/rollup/rollup-tests.ts

@@ -4,7 +4,7 @@ let cache: Bundle | undefined
 
 async function main() {
     const bundle = await rollup({
-        entry: 'main.js',
+        input: 'main.js',
         cache,
     })