Fix/http makeready can reset state

[Julusian]

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

• What is the current behavior? (You can also link to an open issue here)

• What is the new behavior (if this is a feature change)?

• Other information:

[Julusian]

@nytamin as we discussed, there is now a queue in conductor. Instead of using syncFunction, I opted to use an off the shelf queue for promises p-queue. I did look at using syncFunction, but that would have required a fair bit of time to convert it from fibers to promises and this was easier.
I have handled the 'ignore' functionality, by doing the queue.add after the _resolveTimelineRunning guard.
And timeouts for makeReady is handled with the help of p-timeout

Additionally, I went though any uses of Promise.all and they are now using p-all so that it can block until all the child promises have completed and not reject early

[Julusian]

During this I hit what appears to be #139, so have left one use of Promise.all which would be nice to remove also.

Also this appears to break support for node8

[nytamin]

LGTM (pending actual testing ;) )

[codecov-io]

Codecov Report

Merging #142 into master will decrease coverage by 0.03%.
The diff coverage is 64.86%.

@@            Coverage Diff             @@
##           master     #142      +/-   ##
==========================================
- Coverage   76.48%   76.45%   -0.04%     
==========================================
  Files          42       42              
  Lines        4853     4851       -2     
  Branches     1092     1099       +7     
==========================================
- Hits         3712     3709       -3     
- Misses       1097     1098       +1     
  Partials       44       44              

Impacted Files	Coverage Δ
src/devices/casparCG.ts	68.13% <0.00%> (ø)
src/types/src/httpSend.ts	100.00% <ø> (ø)
src/types/src/tcpSend.ts	100.00% <ø> (ø)
src/devices/httpSend.ts	67.50% <57.14%> (+2.56%)	⬆️
src/devices/tcpSend.ts	91.30% <71.42%> (-1.29%)	⬇️
src/conductor.ts	87.24% <93.75%> (-0.26%)	⬇️

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