upgrade_data will write actions for the existing karma values
break upgrade_data into 3 methods for each type of upgrade
All the methods that mutate and/or return terms should now also keep the decay in sync
Migrate vanilla JSON to MultiJson

Strange that it works in the spec, but not in the running app.
Merge branch 'modifier_counts' into karma_decay
Update the documentation to discuss karma decay
Merge branch 'modifier_counts' into karma_decay

Conflicts:
	README.md
	lib/lita/handlers/karma.rb
Merge pull request #9 from erikogan/karma_decay

Karma decay