Add English translation for "unique" validation.

translations/en/en.go

@@ -1293,6 +1293,11 @@ func RegisterDefaultTranslations(v *validator.Validate, trans ut.Translator) (er
 			translation: "{0} must contain a valid MAC address",
 			override:    false,
 		},
+		{
+			tag:         "unique",
+			translation: "{0} must contain unique values",
+			override:    false,
+		},
 		{
 			tag:         "iscolor",
 			translation: "{0} must be a valid color",

translations/en/en_test.go

@@ -138,6 +138,9 @@ func TestTranslations(t *testing.T) {
 		StrPtrGte         *string           `validate:"gte=10"`
 		OneOfString       string            `validate:"oneof=red green"`
 		OneOfInt          int               `validate:"oneof=5 63"`
+		UniqueSlice       []string          `validate:"unique"`
+		UniqueArray       [3]string         `validate:"unique"`
+		UniqueMap         map[string]string `validate:"unique"`
 	}
 
 	var test Test
@@ -184,6 +187,9 @@ func TestTranslations(t *testing.T) {
 	test.StrPtrMaxLen = &s
 	test.StrPtrLen = &s
 
+	test.UniqueSlice = []string{"1234", "1234"}
+	test.UniqueMap = map[string]string{"key1": "1234", "key2": "1234"}
+
 	err = validate.Struct(test)
 	NotEqual(t, err, nil)
 
@@ -614,6 +620,18 @@ func TestTranslations(t *testing.T) {
 			ns:       "Test.OneOfInt",
 			expected: "OneOfInt must be one of [5 63]",
 		},
+		{
+			ns:       "Test.UniqueSlice",
+			expected: "UniqueSlice must contain unique values",
+		},
+		{
+			ns:       "Test.UniqueArray",
+			expected: "UniqueArray must contain unique values",
+		},
+		{
+			ns:       "Test.UniqueMap",
+			expected: "UniqueMap must contain unique values",
+		},
 	}
 
 	for _, tt := range tests {