linter: Enable error checking linter (#766)

* golangci: Enable err checking linter to expose unchecked errors.

* gct: handle errors across the board

* gct: handle errors NOTE: Found bug in FTX (WIP)

* linter: fix issues

* ftx/exchanges: fix bug where error was being returned when setting pair management variables to an already enabled state

* bitmex: fix bug where a dangly supported asset in config danglied up the place.

* linter: fix more linter issues

* linter: fix my terrible spelling.

* currency: fix test

* exchanges: fix tests

* logger: fix test

* exchanges: fix tests

* glorious: nits

* vm: revert rm variable and instigate test

currency/code_test.go

@@ -245,12 +245,15 @@ func TestBaseCode(t *testing.T) {
 			true)
 	}
 
-	main.LoadItem(&Item{
+	err = main.LoadItem(&Item{
 		ID:       0,
 		FullName: "Cardano",
 		Role:     Cryptocurrency,
 		Symbol:   "ADA",
 	})
+	if err != nil {
+		t.Fatal(err)
+	}
 
 	full, err := main.GetFullCurrencyData()
 	if err != nil {