Linter fails if adding a file from another project while preserving copyright

[mmatache]

This issue relates to: #596

During the implementation, the util functions from Jaeger were used, but since they were small, it was decided to simply copy the files over so as to not add a dependency.

The problem is that we were not able to properly preserve the Jaeger copyright as the goheader linter would error out:

make lint
golangci-lint run
pkg/naming/dns.go:2:4: Actual: Copyright The Jaeger Authors.
Expected: (goheader)
// Copyright The Jaeger Authors.
   ^
make: *** [Makefile:114: lint] Error 1

As such I am opening this ticket to try and figure out a solution for this, as this situation might arise again.

[pavolloffay]

Done in #609