Add "not null" constraint to timestamp columns.
-rw-r--r-- 9 .gitignore
drwxr-xr-x - apps
drwxr-xr-x - crunch_scripts
drwxr-xr-x - doc
drwxr-xr-x - docker
drwxr-xr-x - sdk
drwxr-xr-x - services