add config

config/loader/memory/options.go

@@ -0,0 +1,21 @@
+package memory
+
+import (
+	"github.com/micro/go-micro/config/loader"
+	"github.com/micro/go-micro/config/reader"
+	"github.com/micro/go-micro/config/source"
+)
+
+// WithSource appends a source to list of sources
+func WithSource(s source.Source) loader.Option {
+	return func(o *loader.Options) {
+		o.Source = append(o.Source, s)
+	}
+}
+
+// WithReader sets the config reader
+func WithReader(r reader.Reader) loader.Option {
+	return func(o *loader.Options) {
+		o.Reader = r
+	}
+}