Index creation for capped collection fails

[j13z]

Hi,

I found an issue in the createCollection function that results in an unhandled promise rejection when using a capped collection ({ … capped: true, cappedMax: <n> … }) without TTL (expireAfterSeconds not set). There's a bug in the conditional at line 118, which causes the deletion of a non-existing index:

https://github.com/winstonjs/winston-mongodb/blob/master/lib/winston-mongodb.js#L118

With MongoDB 3.0.14, the indexInformation response has no expireAfterSeconds property, i.e. undefined, but self.expireAfterSeconds is false.

I created a pull request (#88) that fixes the issue. Would be nice if you could merge it and create a patch release. Thanks.

[yurijmikhalevich]

Merged. Published. Thank you.