Sdk element in MSBuild project causes InvalidProjectFileException on load

[natemcmaster]

OmniSharp cannot parse projects that use the <Sdk> element under project. (I believe this is new in MSBuild 15.3)

Repro

<Project>
  <Sdk Name="Microsoft.NET.Sdk" />
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp2.0</TargetFramework>
  </PropertyGroup>
</Project>

Error

Microsoft.Build.Exceptions.InvalidProjectFileException: The element <Sdk> beneath element <Project> is unrecognized.  /private/tmp/tst/tst.csproj
...

 at Microsoft.Build.Evaluation.ProjectCollection.LoadProject (System.String fileName, System.String toolsVersion) [0x00001] in <bdf083ca20c84af487947992fd9a4a29>:0 
  at Microsoft.Build.Evaluation.ProjectCollection.LoadProject (System.String fileName) [0x00001] in <bdf083ca20c84af487947992fd9a4a29>:0 
  at OmniSharp.MSBuild.ProjectFile.ProjectFileInfo.LoadProject (System.String filePath, System.String solutionDirectory, System.String sdksPath, Microsoft.Extensions.Logging.ILogger logger, OmniSharp.Options.MSBuildOptions options, System.Collections.Generic.ICollection`1[T] diagnostics, System.Collections.Immutable.ImmutableArray`1[System.String]& targetFrameworks) [0x00062] in <4547000d373140b29fc6ad48137693ba>:0 
  at OmniSharp.MSBuild.ProjectFile.ProjectFileInfo.Create (System.String filePath, System.String solutionDirectory, System.String sdksPath, Microsoft.Extensions.Logging.ILogger logger, OmniSharp.Options.MSBuildOptions options, System.Collections.Generic.ICollection`1[T] diagnostics) [0x0000a] in <4547000d373140b29fc6ad48137693ba>:0 
  at OmniSharp.MSBuild.MSBuildProjectSystem.LoadProject (System.String projectFilePath) [0x0003f] in <4547000d373140b29fc6ad48137693ba>:0 

Details:
macOS Sierra
mono: not installed
dotnet: 2.0.0-preview2-006497
VS Code: 1.13.1
C# extension: 1.12.0-beta1

[DustinCampbell]

Thanks @natemcmaster! I need to update OmniSharp's build of MSBuild to get this feature.