Allow for clearing a module from cache

Upsilon/ModuleHandler.cs

@@ -21,5 +21,10 @@ namespace Upsilon
             _cachedModules.Add(name, module);
             return module;
         }
+
+        public void ClearCachedModule(string name)
+        {
+            _cachedModules.Remove(name);
+        }
     }
 }