promu is useless in Makefile because it builds but we already do
`go install`.

Current CI configuration uses outdated Ubuntu Trusty and unsupported Go
versions.

This change updates version to Ubuntu Xenial and latest (at the moment
of commit) supported versions of Go.

Currently `go test` is running in "local directory mode". Citing the
`go help test`:

> The first, called local directory mode, occurs when go test is
invoked with no package arguments (for example, 'go test' or 'go
test -v'). In this mode, go test compiles the package sources and
tests found in the current directory and then runs the resulting
test binary.

So no actual tests are run because main package doesn't have any.

This commit adds testing of all packages by adding `./...` argument to
test command. It also adds spinning up docker-compose to make tests pass
because the tests need to query real Clickhouse instance.

goreleaser is used for making GitHub releases on tag push so people
could download the prebuilt binaries and Linux packages.

goreleaser will create GitHub release with:

* Binaries for Linux and Darwin for amd64 and i386
* Deb and RPM packages for amd64 and i386

Travis CI will invoke goreleaser on tag push that will create GitHub
release with artifacts described in goreleaser config.

To avoid deploy job failure we have to invoke goreleaser from one job
because otherwise GitHub release is already created.

In this commit we add second condition to deploy with the last Go
version.