Update Fantomas to FCS 33 (#568)

* update to FCS 33

* update member flag generation to account for member ranges that are tighter than before

* Re-using existing range helper function

Author: baronfel

paket.dependencies

@@ -3,7 +3,7 @@ source https://www.nuget.org/api/v2/
 storage: none
 
 nuget FSharp.Core
-nuget FSharp.Compiler.Service 32.0.0
+nuget FSharp.Compiler.Service 33.0.0
 nuget FsUnit
 nuget FsCheck
 nuget Microsoft.NET.Test.Sdk