Add a CHANGES.md

To document changes for users

CHANGES.md

@@ -0,0 +1,49 @@
+# Changes in OSEM 2.0
+
+Not release yet...
+
+## Update from 1.0
+
+### Multiple Schedules
+A conference can have multiple schedules now so it's easier for organizers to
+test schedules and collaborate on different versions.
+
+For this some of the existing data needs to be changed. If you update
+from 1.0 please run this rake task to move your old schedules to the
+new system.
+
+```
+bundle exec rake data:move_events_attributes RAILS_ENV=production
+```
+
+### Dropped visit/campaign tracking
+We have dropped the feature to track visits and campaigns (utm parameters)
+inside OSEM. We recommend you use [matomo](https://matomo.org/) for things
+like that. Before you update to OSEM 1.1 you should drop all the data we
+have collected.
+
+```
+bundle exec rake data:drop_all_ahoy_events RAILS_ENV=production
+```
+
+# Changes in OSEM 1.0
+
+[Released May 24, 2016](https://osem.io/1.0)
+
+Our first release after developing and using this app in production for
+many years. Too many changes to list, see the release announcement to
+learn what OSEM is about.
+
+https://osem.io/1.0
+
+## Update from master
+
+### Configuration through the environment
+If you have deployed OSEM from master before there is one thing you need to do
+manually. OSEM is now configured through environment variables and not through
+the config/options.yml anymore. There is a rake task to migrate your existing
+data to a .env file that OSEM will use:
+
+```
+bundle exec rake data:migrate:config2dotenv RAILS_ENV=production
+```