Revisit the disabling of the linter: maligned

[mattysweeps]

There is only one offender: the Config struct.
https://github.com/cloudfoundry-community/stackdriver-tools/blob/master/src/stackdriver-nozzle/config/config.go#L59

Determine if gometalinter should be configured to ignore this file, or if the linter should be permanently disabled, as it might hold little use to the stackdriver-tools project.