Lots of features, first version that reliably crawls Geminispace.

- [x] Concurrent downloading with workers
- [x] Concurrent connection limit per host
- [x] URL Blacklist
- [x] Save image/* and text/* files
- [x] Configuration via environment variables
- [x] Storing snapshots in PostgreSQL
- [x] Proper response header & body UTF-8 and format validation
.

.

logging/logging.go

@@ -0,0 +1,23 @@
+package logging
+
+import (
+	"fmt"
+
+	zlog "github.com/rs/zerolog/log"
+)
+
+func LogDebug(format string, args ...interface{}) {
+	zlog.Debug().Msg(fmt.Sprintf(format, args...))
+}
+
+func LogInfo(format string, args ...interface{}) {
+	zlog.Info().Msg(fmt.Sprintf(format, args...))
+}
+
+func LogWarn(format string, args ...interface{}) {
+	zlog.Warn().Msg(fmt.Sprintf(format, args...))
+}
+
+func LogError(format string, args ...interface{}) {
+	zlog.Error().Err(fmt.Errorf(format, args...)).Msg("")
+}