Reverted all changes to the unit test project

Author: niemyjski

Source/Tests/Exceptionless.Tests.csproj

@@ -52,7 +52,6 @@
     </Reference>
     <Reference Include="Microsoft.Build" />
     <Reference Include="Microsoft.Build.Framework" />
-    <Reference Include="Microsoft.Build.Utilities.v12.0, Version=12.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL" />
     <Reference Include="Microsoft.Build.Utilities.v4.0" />
     <Reference Include="Microsoft.CSharp" />
     <Reference Include="Microsoft.Owin, Version=3.0.1.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
@@ -111,6 +110,7 @@
       <HintPath>..\..\packages\Microsoft.AspNet.WebApi.Client.5.2.3\lib\net45\System.Net.Http.Formatting.dll</HintPath>
       <Private>True</Private>
     </Reference>
+    <Reference Include="System.Runtime" />
     <Reference Include="System.Web.Http, Version=5.2.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
       <HintPath>..\..\packages\Microsoft.AspNet.WebApi.Core.5.2.3\lib\net45\System.Web.Http.dll</HintPath>
       <Private>True</Private>
@@ -135,6 +135,9 @@
       <HintPath>..\..\packages\xunit.extensibility.execution.2.1.0\lib\net45\xunit.execution.desktop.dll</HintPath>
       <Private>True</Private>
     </Reference>
+    <Reference Include="System.Threading.Tasks, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" Condition="'$(TargetFrameworkVersionProperty)' == 'NET40'">
+      <Visible>false</Visible>
+    </Reference>
   </ItemGroup>
   <ItemGroup>
     <Compile Include="..\GlobalAssemblyInfo.cs">