update arviz (#278)

Author: HumphreyYang

environment.yml

@@ -14,7 +14,7 @@ dependencies:
     - ghp-import==1.1.0
     - sphinxcontrib-youtube==1.1.0
     - sphinx-togglebutton==0.3.1
-    - arviz==0.12.1
+    - arviz==0.13.0
     # Sandpit Requirements
     - quantecon
     - array-to-latex