Don't generate default metadata value for MySQL. Closes #16
v0.7.0
RSpec 3
Merge pull request #67 from gocardless/rspec-3

RSpec 3
Fix circle
Merge pull request #68 from gocardless/fix-circle

Fix circle
Add retry_conflicts class method to Machine which automatically retries conflicts
Merge pull request #65 from gocardless/retry-conflicts-functionality

Add option to automatically retry races
initial spec for events
implement events dsl, event trigger
spec for #available_events
return list of available events for a particular state
updated README
remove unneded state from example in readme
update code to comply with rubocop
add messages explaning events transition errors
move event transition to its own file
update events example
Update event specs for Rspec 3 syntax
v0.8.0 (closes #63)