Update golint to revive

Resolves the following message in golangci output:

> The linter 'golint' is deprecated (since v1.41.0) due to: The
repository of the linter has been archived by the owner.  Replaced by
revive.

Additionally, fix a minor linting issue discovered by revive.

Signed-off-by: Justin Chadwell <me@jedevc.com>

.golangci.yml

@@ -18,7 +18,7 @@ linters:
     - misspell
     - unused
     - varcheck
-    - golint
+    - revive
     - staticcheck
     - typecheck
     - structcheck
@@ -36,5 +36,5 @@ linters-settings:
 issues:
   exclude-rules:
     - linters:
-        - golint
+        - revive
       text: "stutters"