Add some APIs.

lib/src/enum/allow_type.dart

@@ -0,0 +1,4 @@
+class AllowType {
+  static const allow = 0;
+  static const notAllow = 1;
+}

lib/src/enum/group_member_filter.dart

@@ -0,0 +1,14 @@
+/// Group Member Filter
+class GroupMemberFilter {
+  static const all = 0;
+
+  static const owner = 1;
+
+  static const admin = 2;
+
+  static const member  = 3;
+
+  static const adminAndMember = 4;
+
+  static const superAndAdmin = 4;
+}

lib/src/enum/group_status.dart

@@ -0,0 +1,7 @@
+/// Group Status
+class GroupStatus {
+  static const normal = 0;
+  static const baned = 1;
+  static const dismissed = 2;
+  static const muted = 3;
+}

lib/src/enum/join_source.dart

@@ -0,0 +1,5 @@
+class JoinSource {
+  static const invited = 2;
+  static const search = 3;
+  static const QRCode = 4;
+}

lib/src/enum/receive_message_opt.dart

@@ -0,0 +1,5 @@
+class ReceiveMessageOpt {
+  static const receive = 0;
+  static const notReceive = 1;
+  static const notNotify = 2;
+}

lib/src/enum/relationship.dart

@@ -0,0 +1,4 @@
+class AllowType {
+  static const black = 0;
+  static const friend = 1;
+}