golangci-lint/CI: Bump versions and introduce new linters (#798)

* golangci-lint/CI: Bump versions

Fix remaining linter issues

* Specifically set AppVeyor version

* Fix the infamous typos 👀

* Add go env cmd to AppVeyor

* Add go version cmd to AppVeyor

* Specify AppVeyor image, adjust linters

* Update go get to go install due to deprecation

* Bump golangci-lint timeout time for AppVeyor

* Change NW contract to NQ

* Address nitters

* GetRandomPair -> Pair{}

* Address nits

* Address time nitterinos plus additional tweaks

* More time inception upgrades!

* Bending time and space

.github/workflows/linter.yml

@@ -9,4 +9,4 @@ jobs:
       - name: golangci-lint
         uses: golangci/golangci-lint-action@v2
         with:
-          version: v1.31
+          version: v1.42.1

.github/workflows/tests.yml

@@ -1,7 +1,7 @@
 on: [push, pull_request]
 name: CI
 env:
-  GO_VERSION: 1.16.x
+  GO_VERSION: 1.17.x
 jobs:
   backend-psql:
     name: GoCryptoTrader back-end with PSQL