Bump mongodb from 2.2.36 to 3.6.1
Bump mongodb from 2.2.36 to 3.6.1

Bumps [mongodb](https://github.com/mongodb/node-mongodb-native) from 2.2.36 to 3.6.1.
- [Release notes](https://github.com/mongodb/node-mongodb-native/releases)
- [Changelog](https://github.com/mongodb/node-mongodb-native/blob/master/CHANGES_3.0.0.md)
- [Commits](https://github.com/mongodb/node-mongodb-native/compare/v2.2.36...v3.6.1)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
flitsmeister/geohash-explorer,flitsmeister/geohash-explorer