Update conda_build_config.yaml to bob-devel 2019.08.28

Fixes bob.extension#72 (closed)

bob/devtools/data/conda_build_config.yaml

@@ -51,12 +51,12 @@ zip_keys:
 
 # This version of bob-devel will be used at test time of packages:
 bob_devel:
-  - 2019.08.26
+  - 2019.08.28
 
 # This version of beat-devel will be used at test time of packages. Notice it
 # uses bob-devel and should have a version that is greater or equal its value
 beat_devel:
-  - 2019.08.26
+  - 2019.08.28
 
 # The build time only dependencies (build requirements).
 # Updating these to the latest version all the time is OK and a good idea.