fixme: set log level default to DEBUG

For some reason the log level environment variables aren't being picked
up, and neither is the default value for the flag being applied to the
final binary when run in docker. Remove this commit once a fix is
established.

go/batch-submitter/config.go

@@ -223,6 +223,10 @@ func NewConfig(ctx *cli.Context) (Config, error) {
 // ensure that it is well-formed.
 func ValidateConfig(cfg *Config) error {
 	// Sanity check log level.
+	if cfg.LogLevel == "" {
+		cfg.LogLevel = "debug"
+	}
+
 	_, err := log.LvlFromString(cfg.LogLevel)
 	if err != nil {
 		return err