During tests provide a zaptest Logger so all services output will be redirected
to golang testing logger.
When multiple services of the same type are provided add a unique name field to
distinguish them.
* Delete the command and it's rule in the Makefile
* Don't use it inside gitserver and remove related config option (also from
examples)
* Remove webhook parsing from agolagit gitsource
Just a raw replace of "github.com/pkg/errors".
Next steps will improve errors (like remote errors, api errors, not exist errors
etc...) to leverage its functionalities
