small refactor the interface, use contructors instead of pointers for entry

dictionary.go

@@ -1,21 +1,13 @@
 package jiebago
 
-type Pair struct {
+type Entry struct {
 	Word string
 	Flag string
-}
-
-type Entry struct {
-	*Pair
 	Freq float64
 }
 
-func NewEntry() *Entry {
-	return &Entry{new(Pair), 0.0}
-}
-
 type DictLoader interface {
-	AddEntry(*Entry)
+	AddEntry(Entry)
 }
 
 type Cacher interface {