Fix resolve mscorlib

[KevinRansom]

1. Disable a couple more failing tests.
2. Re-enable CSharpProjectAnalysis tests, and fix the bug.
   Clearly there was a typo in Framework version search, in the simulatedReferenceResolver: https://github.com/Microsoft/visualfsharp/blob/master/src/fsharp/SimulatedMSBuildReferenceResolver.fs#L21

Failures:

Errors and Failures

1) Error : FSharp.Compiler.Service.Tests.CSharpProjectAnalysis.Ctor test
System.Exception : **** error: Assembly reference 'mscorlib.dll' was not found or is invalid
   at FSharp.Compiler.Service.Tests.CSharpProjectAnalysis.getProjectReferences(String content, IEnumerable`1 dllFiles, FSharpOption`1 libDirs, FSharpOption`1 otherFlags)
   at FSharp.Compiler.Service.Tests.CSharpProjectAnalysis.Ctor test()

2) Error : FSharp.Compiler.Service.Tests.CSharpProjectAnalysis.Different namespaces with the same short name equality check
System.Exception : **** error: Assembly reference 'mscorlib.dll' was not found or is invalid
   at FSharp.Compiler.Service.Tests.CSharpProjectAnalysis.getProjectReferences(String content, IEnumerable`1 dllFiles, FSharpOption`1 libDirs, FSharpOption`1 otherFlags)
   at FSharp.Compiler.Service.Tests.CSharpProjectAnalysis.getEntitiesUses(String source)
   at FSharp.Compiler.Service.Tests.CSharpProjectAnalysis.Different namespaces with the same short name equality check()

3) Error : FSharp.Compiler.Service.Tests.CSharpProjectAnalysis.Different types with the same short name equality check
System.Exception : **** error: Assembly reference 'mscorlib.dll' was not found or is invalid
   at FSharp.Compiler.Service.Tests.CSharpProjectAnalysis.getProjectReferences(String content, IEnumerable`1 dllFiles, FSharpOption`1 libDirs, FSharpOption`1 otherFlags)
   at FSharp.Compiler.Service.Tests.CSharpProjectAnalysis.getEntitiesUses(String source)
   at FSharp.Compiler.Service.Tests.CSharpProjectAnalysis.Different types with the same short name equality check()

4) Error : FSharp.Compiler.Service.Tests.CSharpProjectAnalysis.Test that csharp references are recognized as such
System.Exception : **** error: Assembly reference 'mscorlib.dll' was not found or is invalid
   at FSharp.Compiler.Service.Tests.CSharpProjectAnalysis.getProjectReferences(String content, IEnumerable`1 dllFiles, FSharpOption`1 libDirs, FSharpOption`1 otherFlags)
   at FSharp.Compiler.Service.Tests.CSharpProjectAnalysis.Test that csharp references are recognized as such()

5) Error : FSharp.Compiler.Service.Tests.CSharpProjectAnalysis.Test that symbols of csharp inner classes/enums are reported
System.Exception : **** error: Assembly reference 'mscorlib.dll' was not found or is invalid
   at FSharp.Compiler.Service.Tests.CSharpProjectAnalysis.getProjectReferences(String content, IEnumerable`1 dllFiles, FSharpOption`1 libDirs, FSharpOption`1 otherFlags)
   at FSharp.Compiler.Service.Tests.CSharpProjectAnalysis.Test that symbols of csharp inner classes/enums are reported()

[KevinRansom]

@dotnet-bot test Ubuntu16.04 Release_fcs Build please

[KevinRansom]

@dsyme, can you take a look at this. I'm pulling it because the build is broken, because I reactivated slightly too many tests and it fixes the broken build.

[dsyme]

I think the tests are still enabled in the FCS build, or I expect so. But yes we should re=enable them for Visual FSharp Unit tests too