Provide Client interface

src/main/java/com/pusher/client/Client.java

@@ -0,0 +1,33 @@
+package com.pusher.client;
+
+import com.pusher.client.channel.Channel;
+import com.pusher.client.channel.ChannelEventListener;
+import com.pusher.client.channel.PresenceChannel;
+import com.pusher.client.channel.PresenceChannelEventListener;
+import com.pusher.client.channel.PrivateChannel;
+import com.pusher.client.channel.PrivateChannelEventListener;
+import com.pusher.client.connection.Connection;
+import com.pusher.client.connection.ConnectionEventListener;
+import com.pusher.client.connection.ConnectionState;
+
+/**
+ * Created by jamiepatel on 09/06/2016.
+ */
+public interface Client {
+    Connection getConnection();
+    void connect();
+    void connect(final ConnectionEventListener eventListener, ConnectionState... connectionStates);
+    void disconnect();
+    Channel subscribe(final String channelName);
+    Channel subscribe(final String channelName, final ChannelEventListener listener, final String... eventNames);
+    PrivateChannel subscribePrivate(final String channelName);
+    PrivateChannel subscribePrivate(final String channelName, final PrivateChannelEventListener listener,
+                                    final String... eventNames);
+    PresenceChannel subscribePresence(final String channelName);
+    PresenceChannel subscribePresence(final String channelName, final PresenceChannelEventListener listener,
+                                      final String... eventNames);
+    void unsubscribe(final String channelName);
+    Channel getChannel(String channelName);
+    PrivateChannel getPrivateChannel(String channelName);
+    PresenceChannel getPresenceChannel(String channelName);
+}

src/main/java/com/pusher/client/Pusher.java

@@ -33,7 +33,7 @@
  * {@link Pusher#subscribePresence(String)} or one of the overloads.
  * </p>
  */
-public class Pusher {
+public class Pusher implements Client {
 
     private final PusherOptions pusherOptions;
     private final InternalConnection connection;