Added picamera import checker

openflexure_microscope/rescue/check_picamera.py

@@ -0,0 +1,15 @@
+import logging
+
+def main():
+    error_sources = []
+    logging.info("Attempting to import picamera...")
+
+    try:
+        from picamerax import PiCamera
+    except Exception as e:  # pylint: disable=W0703
+        # TODO: Parse exception object for a few different issues, and append different error sources
+        # E.g. pi with camera already in use, disconnected, unsupported OS, etc
+        logging.error(e)
+        error_sources.append("picamera_import_error")
+
+    return error_sources