ISubscription should inherit IDisposable (#438)

Signed-off-by: Colin Sullivan <[email protected]>

src/NATS.Client/IAsyncSubscription.cs

@@ -12,9 +12,6 @@
 // limitations under the License.
 
 using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
 
 namespace NATS.Client
 {
@@ -26,7 +23,7 @@ namespace NATS.Client
     /// If the <see cref="IAsyncSubscription"/> is created without listening to the <see cref="MessageHandler"/>
     /// event, no messages will be received until <see cref="Start()"/> has been called.
     /// </remarks>
-    public interface IAsyncSubscription : ISubscription, IDisposable
+    public interface IAsyncSubscription : ISubscription
     {
         /// <summary>
         /// Occurs when the <see cref="IAsyncSubscription"/> receives a message from the

src/NATS.Client/ISubscription.cs

@@ -11,6 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+using System;
 using System.Threading.Tasks;
 
 namespace NATS.Client
@@ -26,7 +27,7 @@ namespace NATS.Client
     /// </remarks>
     /// <seealso cref="ISyncSubscription"/>
     /// <seealso cref="IAsyncSubscription"/>
-    public interface ISubscription
+    public interface ISubscription : IDisposable
     {
         /// <summary>
         /// Gets the subject for this subscription.

src/NATS.Client/ISyncSubscription.cs

@@ -19,7 +19,7 @@ namespace NATS.Client
     /// <see cref="ISyncSubscription"/> provides messages for a subject through calls
     /// to <see cref="NextMessage()"/> and <see cref="NextMessage(int)"/>.
     /// </summary>
-    public interface ISyncSubscription : ISubscription, IDisposable
+    public interface ISyncSubscription : ISubscription
     {
         /// <summary>
         /// Returns the next <see cref="Msg"/> available to a synchronous