chore: updated the minimum version of node from 8.0.0 to 8.5.0

[Ema93sh]

Which problem is this PR solving?

#711

Short description of the changes

Updated the minimum version of nodeJS support from 8.0.0 to 8.5.0

[dyladan]

Can you please also add to the README that our minimum supported version is 8.5.0 and that the maximum supported version is 12

[codecov-io]

Codecov Report

Merging #764 into master will increase coverage by 5.37%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #764      +/-   ##
==========================================
+ Coverage   90.57%   95.95%   +5.37%     
==========================================
  Files         239      130     -109     
  Lines       11684     5860    -5824     
  Branches     1098      539     -559     
==========================================
- Hits        10583     5623    -4960     
+ Misses       1101      237     -864

Impacted Files	Coverage Δ
packages/opentelemetry-plugin-http/src/http.ts	97.72% <ø> (ø)	⬆️
...telemetry-core/src/context/propagation/B3Format.ts	94.59% <100%> (-2.91%)	⬇️
...try-propagator-jaeger/src/JaegerHttpTraceFormat.ts	95.65% <100%> (ø)	⬆️
...y-core/src/context/propagation/HttpTraceContext.ts	100% <100%> (ø)	⬆️
...-api/src/context/propagation/NoopHttpTextFormat.ts	100% <100%> (ø)	⬆️
...opagator-jaeger/test/JaegerHttpTraceFormat.test.ts	100% <0%> (ø)	⬆️
...ges/opentelemetry-plugin-https/test/utils/utils.ts	33.33% <0%> (-26.67%)	⬇️
...ckages/opentelemetry-core/src/common/NoopLogger.ts	40% <0%> (-57.73%)	⬇️
...opentelemetry-core/src/platform/node/timer-util.ts	50% <0%> (-45.32%)	⬇️
...emetry-plugin-https/test/utils/DummyPropagation.ts	100% <0%> (ø)	⬆️
... and 178 more

[Ema93sh]

Can you please also add to the README that our minimum supported version is 8.5.0 and that the maximum supported version is 12

Is there any section of the README that you recommend putting the supported version in. I put it in About this project for now. let me know otherwise

[Ema93sh]

@dyladan Can you help me debug why its failing in CI when you get a chance? I dont have access to it and circleci build --job node8 works for me locally. My best guess from seeing the logs is that CI is trying to fetch from cache instead of remote and it fails

[dyladan]

This is no longer needed as we have addressed the support matrix