Remove mongolab references

[rlondner]

Would it be possible to replace the mongolab connection strings with MongoDB Atlas connection strings?

The relevant files are the following:

• https://github.com/jeroen/mongolite/blob/master/readme.md
• https://github.com/jeroen/mongolite/blob/master/R/mongo.R
• https://jeroen.github.io/mongolite/connecting-to-mongodb.html
• https://cran.r-project.org/web/packages/mongolite/mongolite.pdf
• https://ropensci.org/blog/2017/03/10/mongolite/

Thank you, Raphael.

[jeroen]

This is fixed in mongolite 2.0.