Added Unsubscribe method

Clarified contribution license requirements in readme

README.md

@@ -68,3 +68,6 @@ Master build (stable release)
 
 Latest build
 [![Build status](https://ci.appveyor.com/api/projects/status/cyuo0vm7admy0d9x?svg=true)](https://ci.appveyor.com/project/MvRens/tapeti)
+
+## Contributing
+By contributing to Tapeti's main repository (https://github.com/MvRens/Tapeti) you agree to dedicate your code-base contributions to the public domain under the Unlicense license.

Tapeti/IConnection.cs

@@ -84,6 +84,12 @@ namespace Tapeti
         ISubscriber SubscribeSync(bool startConsuming = true);
 
 
+        /// <summary>
+        /// Stops the current subscriber.
+        /// </summary>
+        Task Unsubscribe();
+
+
         /// <summary>
         /// Returns an IPublisher implementation for the current connection.
         /// </summary>

Tapeti/TapetiConnection.cs

@@ -80,6 +80,13 @@ namespace Tapeti
         }
 
 
+        /// <inheritdoc />
+        public Task Unsubscribe()
+        {
+            return subscriber?.Stop() ?? Task.CompletedTask;
+        }
+
+
         /// <inheritdoc />
         public IPublisher GetPublisher()
         {