Added parserOptions option

[51ck]

Hi there!

Today I have faced an issue:

[!] (plugin rename-rollup) SyntaxError: Unexpected token (row:column)
undefined (row:column)
SyntaxError: Unexpected token (row:column)
    at Parser.pp$4.raise (/project/node_modules/rollup/dist/shared/rollup.js:19613:13)
    at Parser.pp$9.unexpected (/project/node_modules/rollup/dist/shared/rollup.js:16908:8)
    at Parser.pp$5.parseIdent (/project/node_modules/rollup/dist/shared/rollup.js:19544:10)
    at Parser.pp$5.parsePropertyName (/project/node_modules/rollup/dist/shared/rollup.js:19347:109)
    at Parser.pp$5.parseProperty (/project/node_modules/rollup/dist/shared/rollup.js:19274:8)
    at Parser.pp$5.parseObj (/project/node_modules/rollup/dist/shared/rollup.js:19228:21)
    at Parser.pp$5.parseExprAtom (/project/node_modules/rollup/dist/shared/rollup.js:18963:17)
    at Parser.pp$5.parseExprSubscripts (/project/node_modules/rollup/dist/shared/rollup.js:18779:19)
    at Parser.pp$5.parseMaybeUnary (/project/node_modules/rollup/dist/shared/rollup.js:18745:17)
    at Parser.pp$5.parseExprOps (/project/node_modules/rollup/dist/shared/rollup.js:18672:19)
    at Parser.pp$5.parseMaybeConditional (/project/node_modules/rollup/dist/shared/rollup.js:18655:19)
    at Parser.pp$5.parseMaybeAssign (/project/node_modules/rollup/dist/shared/rollup.js:18622:19)
    at Parser.pp$8.parseVar (/project/node_modules/rollup/dist/shared/rollup.js:17451:24)
    at Parser.pp$8.parseVarStatement (/project/node_modules/rollup/dist/shared/rollup.js:17315:8)
    at Parser.pp$8.parseStatement (/project/node_modules/rollup/dist/shared/rollup.js:17063:17)
    at Parser.pp$8.parseBlock (/project/node_modules/rollup/dist/shared/rollup.js:17384:21)

The reason is ecmaVersion here:

const ast = this.parse(file.code, {
    ecmaVersion: 6,
    sourceType: 'module',
});

Proposal: make an option to pass the parser config