register IToaster as scoped service

v0.6.1

Toast transitions based on CSS Animations

This release contains the new transitions logic which is now based on CSS animations and removes most of the System.Threading.Timer calls. There are a few breaking changes:

• the IToaster service is now registered as scoped instead of singleton
• some configuration options used by the old c# transitions have been removed
  • ShowStepDuration
  • HideStepDuration
  • ProgressBarStepDuration

Issues closed:

• closes #15