Use http keep-alive in collector exporter

[srikanthccv]

Fixes #1638

[codecov]

Codecov Report

Merging #1661 (bfe4788) into master (d113742) will increase coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1661      +/-   ##
==========================================
+ Coverage   92.17%   92.18%   +0.01%     
==========================================
  Files         167      167              
  Lines        5594     5594              
  Branches     1191     1191              
==========================================
+ Hits         5156     5157       +1     
+ Misses        438      437       -1     

Impacted Files	Coverage Δ
...emetry-core/src/platform/node/RandomIdGenerator.ts	93.75% <0.00%> (+6.25%)	⬆️

[mwear]

I had a couple of questions, but otherwise this looks to be on track. Perhaps others can chime in with opinions.

[vmarchaud]

Would be nice to have a test that verify that it correctly re-use connections

[dyladan]

I haven't seen any updates since the last round of code reviews. Is this still in progress?

[srikanthccv]

@dyladan I have made progress on this. I am having a little confusion with platform specific and package wise codebase. I am also looking about adding tests for this.

[obecny]

pls resolve the conflicts so we can merge it, thx

[srikanthccv]

pls resolve the conflicts so we can merge it, thx

@obecny Resolved. There one test failing in node12 : Error: Timeout of 2000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves.. I think this is not related to changes from this PR.