Updated motivation video to PyData global talk

Author: seanlaw

docs/motivation.rst

@@ -2,10 +2,10 @@
 Background & Motivation
 -----------------------
 
-The following video from May 2019, provides the background and motivation for developing and open sourcing STUMPY:
+The following video provides the background and motivation for developing and open sourcing STUMPY:
 
 .. raw:: html
 
     <div style="position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; height: auto;">
-        <iframe src="https://www.youtube.com/embed/WvaBPSeA_JA" frameborder="0" allowfullscreen style="position: absolute; top: 0; left: 0; width: 100%; height: 100%;"></iframe>
+        <iframe src="https://www.youtube.com/embed/T9_z7EpA8QM" frameborder="0" allowfullscreen style="position: absolute; top: 0; left: 0; width: 100%; height: 100%;"></iframe>
     </div>