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

common/file/archive/zip_test.go

@@ -80,8 +80,7 @@ func TestZip(t *testing.T) {
 	if filepath.Base(o[0]) != "binance.json" || filepath.Base(o[4]) != "localbitcoins.json" {
 		t.Fatal("unexpected archive result received")
 	}
-	expected := 7
-	if len(o) != expected {
+	if expected := 7; len(o) != expected {
 		t.Fatalf("expected %v files to be extracted received: %v ", expected, len(o))
 	}
 

common/file/file.go

@@ -116,8 +116,7 @@ func WriteAsCSV(filename string, records [][]string) error {
 
 	w.Flush()
 
-	err := w.Error()
-	if err != nil {
+	if err := w.Error(); err != nil {
 		return err
 	}
 	return Write(filename, buf.Bytes())