Coveralls broken for Node 11

[Neitsch]

@IvanGoncharov already found this, but adding tracking here: Coveralls appears to be broken for Node 11 on Travis. Sample Travis log: https://travis-ci.org/graphql/graphql-js/jobs/482864463

At this point it is unclear why Node 11 specifically is broken.

[IvanGoncharov]

@Neitsch Thanks for the opening issue 👍
It's not the first time we had problems with coveralls and it looks like it's abandoned
https://github.com/lemurheavy/coveralls-public/issues
Plus API in constant "Degraded Performance" state:

I did a quick search and it looks like Babel and some other projects switched to codecov
https://github.com/marketplace/codecov
+ it has a few useful features missing in coveralls
I already contacted FB engineers about possibility to set it up for graphql org.

[Neitsch]

@mjmahone I still don't see reports showing up. Could nyc be broken, so that the coverage report does not work? I believe coveralls was complaining about an empty report before we switched.

[IvanGoncharov]

@Neitsch I finally manage to make it work:
https://codecov.io/gh/graphql/graphql-js/tree/5a957cc7efecf642143d33e2be239c76be5c82b7/src
Currently trying to isolate fix and understand what was root cause.

[IvanGoncharov]

@Neitsch Finally nailed it. Update from node 11.6 to node 11.7 broke coverage.
It was bad luck that it coincides with my experiments with disabling on coverage in #1173.
So the problem was nothing to do with coverall or #1173 it was just Travis switching node 11.6 to node 11.7.

[mjmahone]

@IvanGoncharov should we switch back to coveralls in that case? Or perhaps upload to both for the time being?

We have a lot of historical information still in coveralls, so it may be worth generating both reports if possible.

[IvanGoncharov]

should we switch back to coveralls in that case?

@mjmahone Coveralls was lagging from time to time and it forced me to manually review Travis logs every time + it has a few annoying UI quirks that were constantly pestering me.

But most importantly codecov has some very useful features that coveralls lacks. For example, ability to have a separate report for Flow type coverage: facebook/flow#3231

We have a lot of historical information still in coveralls, so it may be worth generating both reports if possible.

All historical data will stay on coverall intact until someone removes account.
Depending on two services makes package.json more complex and introducing more points of failure.

Let's try codecov for some time and if we experience any practical scenarios where coverall will be useful we can always reenable it.