Fix warnings in unit tests flagged by MSBuild Log

Suppressed:
CA1707:Identifiers should not contain underscores
CA1034:Nested types should not be visible

Author: jcansdale

test/GitHub.Exports.UnitTests/GlobalSuppressions.cs

@@ -0,0 +1,9 @@
+
+// This file is used by Code Analysis to maintain SuppressMessage 
+// attributes that are applied to this project.
+// Project-level suppressions either have no target or are given 
+// a specific target and scoped to a namespace, type, member, etc.
+
+[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Naming", "CA1707:Identifiers should not contain underscores", Justification = "Unit test names can contain a _")]
+[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1034:Nested types should not be visible", Justification = "Nested unit test classes should be visible", Scope = "type")]
+