Fix linters warnings
Fix linters warnings

*pkg/isgdnix/isgdnix.go:5:1:warning: package comment should be of the form "Package isgdnix ..." (golint)
*pkg/isgdnix/isgdnix.go:22:2:warning: don't use ALL_CAPS in Go names; use CamelCase (golint)
*pkg/isgdnix/isgdnix.go:22:2:warning: exported const ISGD_BASE should have comment (or a comment on this block) or be unexported (golint)
*pkg/isgdnix/isgdnix.go:23:2:warning: don't use ALL_CAPS in Go names; use CamelCase (golint)
*pkg/isgdnix/isgdnix.go:24:2:warning: don't use ALL_CAPS in Go names; use CamelCase (golint)
*pkg/isgdnix/isgdnix.go:26:2:warning: don't use ALL_CAPS in Go names; use CamelCase (golint)
*pkg/isgdnix/isgdnix.go:27:2:warning: don't use ALL_CAPS in Go names; use CamelCase (golint)
*pkg/isgdnix/isgdnix.go:30:1:warning: comment on exported function Short should be of the form "Short ..." (golint)
* pkg/isgdnix/isgdnix.go:41:1:warning: comment on exported function Lookup should be of the form "Lookup ..." (golint)

nixusr/isgdnix