core: correctly locate maxRetries option - #1358

Changes Unknown when pulling 06b5e17 on stephenplusplus:spp--1357 into * on GoogleCloudPlatform:master*.

@coveralls what can we do to make you happy?

I know we decided to not add system tests for every service in regards to this, but maybe one grpc system test test would benefit us here. WDYT?

What would the system test look like?

I was going to suggest mitm but I now remember that doesn't work with grpc requests. Is this basically untestable (outside of unit tests)?

Yeah, we are just going on trust that retry-request works. Which sounds worse than it is. That's essentially what we do with all of our dependencies... we scope them out, see if the code looks good, that it's tested... then if we trust it, we let its own test suite worry about covering features that it says it offers.

But yeah, testing that we do retry logic when we get a retry-able response from gRPC is quite untestable. I don't think we can control when gRPC will give us, so it's just meant to stay in unit testing-land.