default to using useUnifiedTopology option

[bobmoff]

More info here: https://github.com/mongodb/node-mongodb-native/releases

[mpangrazzi]

can you add one or more tests as for useNewUrlParser option?

[codecov-io]

Codecov Report

Merging #277 into master will increase coverage by 0.02%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #277      +/-   ##
==========================================
+ Coverage   94.81%   94.84%   +0.02%     
==========================================
  Files           6        6              
  Lines         386      388       +2     
==========================================
+ Hits          366      368       +2     
  Misses         20       20

Impacted Files	Coverage Δ
lib/manager.js	95.55% <100%> (+0.06%)	⬆️

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[bobmoff]

can you add one or more tests as for useNewUrlParser option?

done!

[mathieudutour]

Hum that's a breaking change, isn't it?
What's the reason to default to true?

[bobmoff]

DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to MongoClient.connect.

[mpangrazzi]

@mathieudutour IMHO it seems to be very similar to useNewUrlParser option. It's due to an internal change in mongodb module, and it's not listed as a breaking change in their docs.