Implement produce service

internal/interfaces/ramdb.go

@@ -0,0 +1,10 @@
+package interfaces
+
+import "github.com/davidlick/supermarket-api/pkg/ramdb"
+
+type RamDB interface {
+	Get(column, key string) (r *ramdb.Record, err error)
+	Select(column string) (rr []*ramdb.Record, err error)
+	Insert(r *ramdb.Record) error
+	Delete(r *ramdb.Record) error
+}