* .build.yml: update and fix

* auth/casbin: update to accommodate change in dep

* .travis.yml: 1.x and tip

* sd/dnssrv: fix Instancer method receivers

* sd/dnssrv: SRV record with port 0 is an error

* sd/dnssrv: test for SRV port zero issue

* .build.yml: update and fix

* make go vet happy (renamed example function for syslog)

* adjust Zipkin OpenTracing example to use the new bridge version of zipkin-go-opentracing

* fix expected output from kit-gen due to change in gofmt handling of imports

Rate limiting examples might be a bit confusing when Every
method is used #698.
One could expect to see throttling expressed as
a number of requests per unit of time whereas another would see it
as an interval between requests.

The go.mod file was generated with the following sequence of commands:

go mod init
go mod tidy

The first try resulted in two problems.

- One problem was fixed by updating the import path of nats-server to
  use semantic import v2 in transport/nats/subscriber_test.go.
- The other problem was fixed by changing the required version of
  go.etcd.io/etcd to v0.0.0-20191023171146-3cf2f69b5738 which
  corresponds to v3.4.3. We cannot use the v3.4.3 tag directly because
  of problems within the etcd repo itself described in
  etcd-io/etcd#11154

After those two changes a second go mod tidy succeeds and produces the
go.mod file included in this commit.

Performed by deleteding all lines marked // indirect in the go.mod file
and running go mod tidy to restore the required entries.

The entries ultimately removed were probably a remnant of a prior state
of the go.mod file in this sequence.

Add go.mod file

Fix typo: "thte" -> "the"

* Add a span name getter to opencensus endpoint options

* Add GetSpanDetails option

* Split GetSpanDetails function

* Simplify getting the name

* Improve documentation

* Simplify attributes

* Update documentation

* Update tracing/opencensus/endpoint_options.go

Co-authored-by: Peter Bourgon <peterbourgon@users.noreply.github.com>