Angelos Evripiotis authored Nov 26, 2018 and Angelos Evripiotis committed Dec 13, 2018

Update the section on adding tests, to fulfill these broad points:

- Mandate end-to-end testing, with rationale.
- Mention internal APIs as endpoints for testing.
- Warn against pitfalls of unit-testing.

It's more text than I would have liked, perhaps in later work we'll be
able to say it with less.

This change integrates feedback from the mailing list
'Guidance on Unit Tests' thread:
https://mail.gnome.org/archives/buildstream-list/2018-November/msg00045.html

contributing: more clarity on testing

See merge request !973

This is used when sending execution requests, to specify which instance of the
execution server to use.

Partial fix for #627.

Adds instance name support for the remote execution storage service.

Adds the 'instance_name' parameter, which may be None, to most GRPC
calls in the CASCache object. ByteStream requests already have
instance_name supplied in the resource name, so do not need the
parameter.

Closes #627.