Add MongoMemoryReplSet support

[arisjulio]

• Add replica set support. It just need to add the replSet field in jest-mongodb-config.js to start working as a replica set.
• Add test script with replica set enabled

Resolve #152

[vladholubiev]

Thanks for the contribution, @arisjulio!

Would you mind adding a couple of words about this option to the README?

[arisjulio]

Would you mind adding a couple of words about this option to the README?

I'll do it before merging

[arisjulio]

@vladgolubev

Would you mind adding a couple of words about this option to the README?

Done!

[vladholubiev]

@arisjulio thanks!

Published! https://github.com/shelfio/jest-mongodb/releases/tag/v2.2.0

[dozgunyal]

Hi, this seems great, Thank you!!!

We now get "MongoError: database name must be a string." errors when we try to connect to replSet.

module.exports = { 
  mongodbMemoryServerOptions: {
    binary: {
      version: '4.0.10',
      skipMD5: true
    },
    autoStart: false,
    instance: {
      dbName: 'jest'
    },
    replSet: {
      count: 3,
      storageEngine: 'wiredTiger',
    },
  }
};

We tried with and without dbName in instance.

It seems database name is not in the MONGO_URI.
Are we doing something wrong or could you add the database name in the URI?

Should I open a new issue?