Fix an issue where Event.define_slug() would not remove underscores
Fix an issue where Event.define_slug() would not remove underscores

ppapadeas/wprevents,yvan-sraka/wprevents,yvan-sraka/wprevents,ppapadeas/wprevents,ppapadeas/wprevents,yvan-sraka/wprevents,yvan-sraka/wprevents