Use custom .golangci.yml file with improved lint rules

The following discussion from !264 (closed) should be addressed:

• @krasio started a discussion: (+2 comments)

  Is this to avoid name clash with the client package?

---

We use automatic linting via golangci-lint with a default set of relaxed rules. To improve the code style we should add a custom .golangci.yml file enabling a set of useful linters.

We can use GitLab's Runner .golangci.yml for consistency or use as a base for the set of rules we want to apply to Pages.

cc @krasio @vshushlin @sean_carroll

---

Linters

From GitLab's Runner .golangci.yml

Linter	Enable in iteration #
bodyclose	2
deadcode	2
dogsled	2
goconst	1
gocyclo	1
goimports	1
golint	1
gosec	1
gosimple	1
govet	1
ineffassign	2
misspell	2
structcheck	2
typecheck	2
unconvert	2
unused	2
varcheck	2
whitespace	2

Other linters to consider

List of supported linters by golangci-lint

Linter	Description
wsl	improve empty line spacing (annoying but makes the code more readable)
interfacer	Linter that suggests narrower interface types
lll	long lines
unparam	Reports unused function parameters
gocritic	The most opinionated Go source code linter
gochecknoinits	This will help with #342

---

MRs

• Add .golangci.yml linter configuration !286 (merged)
• Enable more linters !287 (merged)