Crash when a feature is not present in the test result (with NUnit)

[freeman]

Some of our feature are ignored from our test run.

Pickles crashes with this error :

Unhandled Exception: System.NullReferenceException: Object reference not set to
an instance of an object.
   at PicklesDoc.Pickles.TestFrameworks.NUnitResults.GetFeatureResult(Feature fe
ature)
   at PicklesDoc.Pickles.Runner.<>c__DisplayClass1.<ApplyTestResultsToFeatures>b
__0(INode node)
   at NGenerics.Patterns.Visitor.ActionVisitor`1.Visit(T obj)
   at NGenerics.Patterns.Visitor.VisitorExtensions.AcceptVisitor[T](IEnumerable`
1 enumerable, IVisitor`1 visitor)
   at PicklesDoc.Pickles.Runner.ApplyTestResultsToFeatures(IContainer container,
 Configuration configuration, GeneralTree`1 features)
   at PicklesDoc.Pickles.Runner.Run(IContainer container)
   at PicklesDoc.Pickles.CommandLine.Program.Main(String[] args)

in this case.

It seems to be caused because the GetFeatureResult method does not checks for a null return from GetFeatureElement.

I can submit a pull request if you like.

[dirkrombauts]

Thanks - I would be very grateful for a pull request!