Update release version and minot nit spell correction on comments (#392)

src/Microsoft.Azure.ServiceBus/Microsoft.Azure.ServiceBus.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <Description>This is the next generation Azure Service Bus .NET Standard client library that focuses on queues &amp; topics. For more information about Service Bus, see https://azure.microsoft.com/en-us/services/service-bus/</Description>
-    <VersionPrefix>2.0.0</VersionPrefix>
+    <VersionPrefix>3.0.0-preview</VersionPrefix>
     <Authors>Microsoft</Authors>
     <TargetFrameworks>net461;netstandard2.0</TargetFrameworks>
     <AssemblyOriginatorKeyFile>../../build/keyfile.snk</AssemblyOriginatorKeyFile>

test/Microsoft.Azure.ServiceBus.UnitTests/RetryTests.cs

@@ -124,7 +124,7 @@ namespace Microsoft.Azure.ServiceBus.UnitTests
             Assert.True(retryExponential.IsServerBusy, "policy1.IsServerBusy is not true");
         }
 
-        [Fact(Skip = "Flaky Test in AppServer, fix and enable back")]
+        [Fact(Skip = "Flaky Test in Appveyor, fix and enable back")]
         async void RunOperationShouldReturnImmediatelyIfRetryIntervalIsGreaterThanOperationTimeout()
         {
             var policy = RetryPolicy.Default;

test/Microsoft.Azure.ServiceBus.UnitTests/SenderReceiverTests.cs

@@ -185,7 +185,7 @@ namespace Microsoft.Azure.ServiceBus.UnitTests
             }
         }
 
-        [Fact(Skip = "Flaky Test in AppServer, fix and enable back")]
+        [Fact(Skip = "Flaky Test in Appveyor, fix and enable back")]
         [DisplayTestMethodName]
         public async Task WaitingReceiveShouldReturnImmediatelyWhenReceiverIsClosed()
         {