Updated simple plugin test

openflexure_microscope/plugins/testing/plugin.py

@@ -0,0 +1,13 @@
+from openflexure_microscope.plugins import MicroscopePlugin
+
+
+class Plugin(MicroscopePlugin):
+    """
+    A set of default plugins
+    """
+
+    def identify(self):
+        """
+        Tests for access to Microscope.camera, and Microscope.stage
+        """
+        return (self.microscope.camera, self.microscope.stage)