Unit test failure fix for CSHARP-389

Author: Sridhar Nanjundeswaran

MongoDB.DriverUnitTests/Jira/CSharp355Tests.cs

@@ -71,6 +71,13 @@ public void TestDefaultBitmap()
         [Test]
         public void TestBitmap()
         {
+            if (TestEnvironment.IsMono)
+            {
+                // This test does not work in Mono on Ubuntu. Throws a
+                // System.TypeInitializationException on the Bitmap 
+                // construction
+                return;
+            }
             var bitmap = GetTestBitmap();
             var c = new C { I = bitmap, B = bitmap };
             _collection.RemoveAll();