Updated the Amazon Web Service Dependency to the latest version.

servicestack/src/ServiceStackBenchmark.csproj

@@ -41,6 +41,10 @@
     <StartupObject />
   </PropertyGroup>
   <ItemGroup>
+    <Reference Include="AWSSDK, Version=1.5.28.3, Culture=neutral, PublicKeyToken=9f476d3089b52be3, processorArchitecture=MSIL">
+      <SpecificVersion>False</SpecificVersion>
+      <HintPath>..\lib\AWSSDK.1.5.28.3\lib\AWSSDK.dll</HintPath>
+    </Reference>
     <Reference Include="Enyim.Caching">
       <HintPath>..\lib\EnyimMemcached.2.12\lib\net35\Enyim.Caching.dll</HintPath>
     </Reference>