Use mattermost v5 module (#1192)

vendor/github.com/francoispqt/gojay/encode_null.go

@@ -0,0 +1,39 @@
+package gojay
+
+// AddNull adds a `null` to be encoded. Must be used while encoding an array.`
+func (enc *Encoder) AddNull() {
+	enc.Null()
+}
+
+// Null adds a `null` to be encoded. Must be used while encoding an array.`
+func (enc *Encoder) Null() {
+	enc.grow(5)
+	r := enc.getPreviousRune()
+	if r != '[' {
+		enc.writeByte(',')
+	}
+	enc.writeBytes(nullBytes)
+}
+
+// AddNullKey adds a `null` to be encoded. Must be used while encoding an array.`
+func (enc *Encoder) AddNullKey(key string) {
+	enc.NullKey(key)
+}
+
+// NullKey adds a `null` to be encoded. Must be used while encoding an array.`
+func (enc *Encoder) NullKey(key string) {
+	if enc.hasKeys {
+		if !enc.keyExists(key) {
+			return
+		}
+	}
+	enc.grow(5 + len(key))
+	r := enc.getPreviousRune()
+	if r != '{' {
+		enc.writeByte(',')
+	}
+	enc.writeByte('"')
+	enc.writeStringEscape(key)
+	enc.writeBytes(objKey)
+	enc.writeBytes(nullBytes)
+}