Config: Refactor version packages (#1887)

* Config: Move config versions to separate pacakges

* Config: Move version tests to blackbox texts

* Config: Protect registerVersion from overflow

* Config: Protect against version already registered

config/versions/v1/v1_test.go

@@ -0,0 +1,37 @@
+package v1_test
+
+import (
+	"bytes"
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	v1 "github.com/thrasher-corp/gocryptotrader/config/versions/v1"
+)
+
+func TestExchanges(t *testing.T) {
+	t.Parallel()
+	assert.Equal(t, []string{"*"}, new(v1.Version).Exchanges())
+}
+
+func TestUpgradeExchange(t *testing.T) {
+	t.Parallel()
+
+	v := &v1.Version{}
+	in := []byte(`{"name":"Wibble","pairsLastUpdated":1566798411,"assetTypes":"spot","configCurrencyPairFormat":{"uppercase":true,"delimiter":"_"},"requestCurrencyPairFormat":{"uppercase":false,"delimiter":"_","separator":"-"},"enabledPairs":"LTC_BTC","availablePairs":"LTC_BTC,ETH_BTC,BTC_USD"}`)
+	exp := []byte(`{"name":"Wibble","currencyPairs":{"bypassConfigFormatUpgrades":false,"requestFormat":{"uppercase":false,"delimiter":"_","separator":"-"},"configFormat":{"uppercase":true,"delimiter":"_"},"useGlobalFormat":true,"lastUpdated":1566798411,"pairs":{"spot":{"enabled":"LTC_BTC","available":"LTC_BTC,ETH_BTC,BTC_USD"}}}}`)
+
+	out, err := v.UpgradeExchange(context.Background(), in)
+	require.NoError(t, err)
+	require.NotEmpty(t, out)
+	assert.Equal(t, string(exp), string(out))
+}
+
+func TestDowngradeExchange(t *testing.T) {
+	t.Parallel()
+	in := []byte("just leave me alone, mkay?")
+	out, err := new(v1.Version).DowngradeExchange(context.Background(), bytes.Clone(in))
+	require.NoError(t, err)
+	assert.Equal(t, out, in)
+}