adding speaker image for Marina Fischer

Author: escowles

_data/speakers.yml

@@ -469,6 +469,7 @@
     the modern period. She is a recipient of a University of Calgary Teaching Award, and lectures
     frequently in various departments across campus.
   image_alt:
+  image_src: /assets/img/speakers/marina-fischer.jpg
   keynote: false
 - id: matt-bernhardt
   name: Matt Bernhardt