* vendor: update Lumberjack dep
* httpserver/roller: introduce rotate_compress directive
This directive will enable gzip compression provided by [Lumberjack](https://github.com/natefinch/lumberjack/pull/43).
The directive `rotate_compress` can be `true` or `false`, being `false` by default.
* httpserver/roller: remove need to set bool with rotate_compress option
* Use new subdirectives and flatten rolling config
* Set default rotate config
* Set default rolling config (hopefully) errwhere
* Make private
* Flatten errors directive and remove c.IncrNest()
* Don't skip first error log roller subdirective we see
* Remove hadBlock
* Try lumberjack import
* Unname import
- Server types no longer need to store their own contexts; they are
stored on the caddy.Instance, which means each context will be
properly GC'ed when the instance is stopped. Server types should use
type assertions to convert from caddy.Context to their concrete
context type when they need to use it.
- Pass the entire context into httpserver.GetConfig instead of only the
Key field.
- caddy.NewTestController now requires a server type string so it can
create a controller with the proper concrete context associated with
that server type.
Tests still need more attention so that we can test the proper creation
of startup functions, etc.
