Pin mongodb dependency

[mayurkale22]

No description provided.

[codecov-io]

Codecov Report

Merging #309 into master will increase coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #309      +/-   ##
==========================================
+ Coverage   94.72%   94.75%   +0.02%     
==========================================
  Files         114      114              
  Lines        7603     7603              
  Branches      692      692              
==========================================
+ Hits         7202     7204       +2     
+ Misses        401      399       -2

Impacted Files	Coverage Δ
test/test-http2.ts	98.66% <0%> (+1.33%)	⬆️

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[mayurkale22]

Node 6 build started failing ever since mongodb published new version 3.1.11 (10 days before). The error was -> no original function _find to wrap, looks like they have deprecated _find_ cursor method from mongodb-core (3.1.10) which comes with mongodb >= 3.1.11. For now, I have pinned mongodb dependency to previous stable version (3.1.10).

I think next action item should be to replace _find cursor method with next and fix the test cases accordingly.